602
FXUS65 KTFX 221606
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
1006 AM MDT Wed May 22 2024


.SYNOPSIS...

Isolated afternoon and evening thunderstorms develop and move
through the region, again, today. The main impact from these
storms is strong and erratic gusty winds. As the day progresses,
widespread precipitation impacts the region. Significant snow
amounts are forecast for mountain elevations, with wintry impacts
to some lower elevations, as well. This system continues to
impact the region into the early hours of Friday morning.

&&

.UPDATE...

The morning update has been published. Light rain showers are
spreading from west to east this morning. This activity will
increase this afternoon and weak instability will introduce
chances for thunderstorms as well. Severe weather is not expected,
but brief downpours, small hail, and gusty winds can be expected
with the stronger cells in addition to a few lightning strikes.
Winter weather is still expected tonight into Thursday, including
heavy, wet, mountain snow, especially over the central and
southwest mountain passes. All winter highlights are in good shape
and the forecast was freshened with the latest data. - RCG

&&

.AVIATION...
22/12Z TAF Period

Note: The NWS Great Falls Weather Forecast Office manages the
following TAFs: KCTB, KHVR, KGTF, KLWT, KHLN, KBZN, KEKS and KWYS.

All TAFs begin under degrading VFR conditions. The next system
arrives through the day, today. Conditions, ultimately, become
MVFR/IFR/LIFR at all airfields. The initial concern is for lower
elevation rain showers and scattered thunderstorms with higher
elevation snow showers through daylight hours. Snow levels fall down
as low as valley floors at times, tonight. Expect mountain
obscuration.
- Fogleman

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

&&

.HYDROLOGY...

A Flood Watch remains in effect for areas near creeks and streams
over in the Little Belt Little mountains tonight through Friday
morning. Current probabilistic forecasts support one to two inches
of rainfall/liquid equivalent precipitation through Friday. Snow
levels will fluctuate with this weather system, with mostly snow
expected for areas above 6,000 feet. However, there are concerns
for flooding on area creeks and streams given recent
precipitation/saturated soils and at least a portion of the
upcoming precipitation falling as rain at all elevations. Those
near water should be vigilante and ready to seek higher ground if
flooding occurs.

&&

.PREV DISCUSSION...
/ISSUED 430 AM MDT Wed May 22 2024/

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

Today and Tomorrow...An upper level closed area of lower heights
rolls southeastward across The Treasure State. The resultant
impacts include precipitation that enters our region from the
west, and becomes widespread throughout the day, today.
Temperatures cool, and significant amounts of snowfall are
forecast across many of the mountainous regions of central and
southwest Montana. For this reason, most of these mountain regions
are under Winter Storm Warnings, with The Snowy mountains added
under a Winter Storm Warning during the issuance of this forecast.
The probability of snow amounts exceeding 6 inches, is at 80% or
more across our mountain zones. Heavy wet snow may cause damage to
trees and power lines. With the approach of the Memorial Day
Weekend, we are particularly concerned for those who may wish to
venture into the backcountry. The conditions that we are forecasting
are associated with high incidents of hypothermia. Having said this,
our concern is not limited to those in the backcountry. Travel will
be dangerous across some mountain passes. Additionally, some of our
lower elevations are forecast to experience impacts from snow.
Surfaces will be slushy and slippery. This system exits the region
by early Friday morning; however, considering the amount of moisture
forecast, flooding impacts are a concern. Please, see the HYDROLOGY
section below for more details.

Friday through Sunday...Active weather continues with only short
reprieves in moisture. With temperatures warming, most moisture from
the ongoing active weather pattern, falls as rain. having said this,
some mountain snow is forecast, and concerns for those wishing to
recreate in the outdoors over the Memorial Day Weekend, continues.

Monday and Tuesday..The forecast is for warm, dry and mild
conditions, with Tuesday`s low elevation high temperatures
ranging in the mid 70s to low 80s.

Wednesday...The mid week period of next week shows a slight chance
of precipitation; however, confidence is low, as this system is
several days out.
- Fogleman

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  58  37  48  36 /  90  90  80  20
CTB  54  34  51  35 / 100  80  40  30
HLN  59  37  48  36 / 100 100  90  10
BZN  59  32  45  28 /  90 100 100  20
WYS  47  25  41  24 /  80  90  80  20
DLN  57  30  44  26 / 100  90  90  10
HVR  58  37  53  36 /  70  70  40  20
LWT  57  34  43  31 /  80  90  90  20

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
Winter Storm Warning from 6 PM this evening to noon MDT Thursday
for Elkhorn and Boulder Mountains-Northwest Beaverhead County-
Ruby Mountains and Southern Beaverhead Mountains-Southern Rocky
Mountain Front-Upper Blackfoot and MacDonald Pass.

Winter Weather Advisory from midnight tonight to 6 PM MDT
Thursday for Gates of the Mountains.

Flood Watch from 6 PM MDT this evening through Friday morning
for Little Belt and Highwood Mountains.

Winter Storm Warning from 6 PM this evening to 6 PM MDT Thursday
for Big Belt, Bridger and Castle Mountains-Gallatin and Madison
County Mountains and Centennial Mountains-Little Belt and
Highwood Mountains.

Winter Weather Advisory from 6 PM this evening to 6 PM MDT
Thursday for Beaverhead and Western Madison below 6000ft-
Gallatin Valley-Madison River Valley-Missouri Headwaters.

Winter Storm Warning from 6 AM to 6 PM MDT Thursday for Snowy
and Judith Mountains.

&&

$$

http://www.weather.gov/greatfalls