594
FXUS65 KTFX 231745
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
1150 AM MDT Sun Jun 23 2024

Aviation Section Updated

.SYNOPSIS...
Today is the warmest day of the week ahead, with low elevation high
temperatures ranging from the upper 80s to mid 90s, while drying
continues through tomorrow. Gusty winds are forecast, today and
tomorrow, as well. Afternoon and evening thunderstorms develop.
Today, a few thunderstorms may become severe, producing erratic
high winds, large hail and frequent lightning.

&&

.Update...
A warm day is in progress across North Central and Southwestern
Montana ahead of a cold front that will push through the area
today and this evening. While we will have to watch for an
isolated rain shower or thunderstorm across Fergus and Blaine
Counties, recent Hi Res guidance like the HRRR has begun to
suggest that convective initiation will likely be further north
and east, resulting in the expectation of a dry day for us today.
Ludwig

&&

.AVIATION...
23/18Z TAF Period

VFR conditions will prevail across the CWA through the period. Do
expect increasing surface winds over North Central MT this
afternoon. As of now, the best chance for storms are expected to
remain mostly east of a Havre to Lewistown line, thus no storms are
currently in the TAF. Brusda

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

&&

.PREV DISCUSSION...
/ISSUED 453 AM MDT Sun Jun 23 2024/

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

Today and Tomorrow...Begin this Sunday under the influence of
upper level ridging, with an upper level trof approaching from
the west. Temperatures continue to warm, today, and low elevation
highs reach into the 90s across much of the region. North central,
central and southwest Montana, generally, fall under an area of
Minor Heat Risk. This is the level that primarily affects those
individuals who are extremely sensitive to heat. Isolated areas of
central and southwest Montana are included under a Moderate Heat
Risk for today. This is the level of heat that affects most
individuals sensitive to heat, especially those without effective
cooling and/or adequate hydration. Special attention and care
should be given to the young, the elderly and pets. A closed area
of upper level higher heights is located over Texas, and the
associated ridge presses northward into our region. This ridge
adds mass to the approaching trof, causing said trof to pass along
Montana`s northern border. The result is a strong westerly cross
barrier flow that pours into our region. Strong, non-warning
criteria, gusty winds are forecast, especially across the Northern
Rocky Mountain Front and the adjacent plains. Gusty winds
continue into tomorrow. As the day progresses, the atmosphere
becomes more unstable, and afternoon and evening thunderstorms
develop. A few thunderstorms may become severe, as there is a 5%
chance for erratic high winds of 58 mph or more, as well as, a 5%
chance for large hail of an inch or greater in diameter, with some
storms. The best chance for severe thunderstorm activity occurs
across Blaine and Fergus counties. General thunderstorms are
forecast to develop tomorrow afternoon and evening, with the best
chance for thunderstorm development focused more on southwest
Montana and northeastward along Meagher, Judith Basin and Fergus
Counties.

Tuesday and Wednesday...The mid week period is characterized by
warming conditions, courtesy of an overhead ridge, and an upper
level southwesterly flow. Tuesday, is forecast to be a, generally,
quiet summer day. Wednesday, breezy winds, as well as, afternoon
and evening thunderstorms and rain showers are forecast, as the
atmosphere becomes more unstable under the influence of the
dynamics associated with the leading edge of the next upper level
trof.

Thursday and Friday...While the previously mentioned trof rolls
across the region, temperatures cool, gusty winds develop and
wide spread rain showers impact the region. There is a 20% to 40%
chance of afternoon and evening thunderstorm activity.

Saturday and next Sunday...The next upper level ridge moves
quickly through the area, followed by the next trof. Saturday,
looks to be a mild and breezy summer day, while Sunday offers some
more active weather.
-Fogleman

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  90  53  83  48 /   0   0   0   0
CTB  83  48  76  45 /   0   0   0   0
HLN  95  58  88  53 /   0   0   0   0
BZN  93  53  88  49 /  10  10  10   0
WYS  84  47  81  43 /   0   0  10   0
DLN  90  53  87  48 /   0   0   0   0
HVR  92  55  83  50 /  10   0   0   0
LWT  89  53  79  48 /  20  30   0   0

&&

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

&&

$$

http://www.weather.gov/greatfalls