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487
FXUS65 KTFX 250959
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
359 AM MDT Tue Jun 25 2024

.SYNOPSIS...

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Mild and dry weather, with periods of breezy to gusty winds is
forecast for today. Tomorrow will see a return to daily afternoon
and evening rain showers and thunderstorms. A passing system
favors widespread rainfall and some cooler temperatures for the
end of the week.
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&&

.DISCUSSION...

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Note: The forecast area for The National Weather Service Great
Falls Weather Forecast Office includes north central, central and
southwest, Montana.

Today...Under the influence of an upper level ridge, mild and dry
conditions are forecast. Periods of breezy to gusty winds are
forecast, with gusts, generally, remaining below 25 mph.

Tomorrow through Friday...The passing upper level ridge is,
quickly, followed by a low amplitude upper level trof. Increasing
instability favors the daily development of afternoon and evening
thunderstorms, especially Wednesday and Thursday. Some of these
storms could become severe producing strong erratic gusty winds,
large hail and brief heavy downpours. The best chance for severe
thunderstorm activity is, Thursday afternoon and evening, when the
Storm Prediction Center (SPC) includes a portion of our area in a
marginal risk for severe weather. That area includes Meagher,
Judith Basin, Fergus and Blaine Counties, where there is a 5%
chance that Thursday`s storms may produce severe winds of 58 mph,
or more, and/or large hail of an inch, or more, within a 25 mile
radius of any given point. As the afore mentioned trof passes,
widespread rainfall is forecast. Thursday, there is a 25% to 50%
chance for much of our region to receive 0.25" of moisture, with a
15% to 30% chance for much of our region to receive as much as
0.5" of precipitation. Locally, higher amounts are forecast, at
times, in association with thunderstorms. Rainfall continues to
impact north central and central Montana through Friday afternoon,
until the weather producing trof exits the region. By Friday,
north central and central Montana experience below normal
temperatures, with low elevation forecast highs ranging in the mid
50s to mid 60s. Southwest Montana continues to trend warmer, with
low elevation highs ranging in the upper 60s to low 70s.

Saturday...Subsidence and drying, in association with the next
upper level ridge, favors a mild summer day.

Sunday through next Tuesday...The next upper level trof dominates,
favoring a gentle cooling trend with a return of widespread
precipitation.
- Fogleman
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&&

.AVIATION...
25/06Z TAF Period

VFR conditions are forecast to continue through at least 26/06Z
across North Central (KCTB, KHVR), Central (KLWT, KGTF, KHLN), and
Southwest (KBZN, KEKS, KWYS) Montana.

A moderate and dry westerly flow aloft will continue mostly clear
skies across the area with some mountain wave turbulence. As high
pressure aloft builds into the Pacific Northwest after 15Z, the
winds aloft and turbulence will decrease across the area. A more
northwesterly flow aloft will move a weak disturbance and associated
weak Canadian cold front southeast over the plains. The main impact
from this will be an overall shift to more northerly winds. It will
also bring scattered to broken mid-level cloudiness to the plains
between 18Z and 03Z. -Coulston

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

&&

.PRELIMINARY POINT TEMPS/POPS...
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GTF  78  49  88  57 /   0   0  10  30
CTB  74  46  83  54 /   0   0  10  20
HLN  87  55  90  61 /   0   0  20  40
BZN  86  51  86  56 /   0   0  30  30
WYS  81  45  78  49 /  10  10  30  30
DLN  86  50  83  53 /   0   0  30  20
HVR  78  50  86  58 /   0   0   0  30
LWT  74  48  82  55 /   0   0  10  30
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&&

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

$$

http://www.weather.gov/greatfalls