247
FXUS65 KTFX 181009
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
409 AM MDT Tue Jun 18 2024

.SYNOPSIS...

Widespread precipitation pushes off to the east this morning, with
another round of precipitation with a few thunderstorms arriving
this afternoon. Daily precipitation chances remain through the
forecast period, with better chances arriving Friday. Temperatures
gradually warm up, becoming well above average by the weekend.

&&

.DISCUSSION...

Today...Widespread rain and mountain snow showers will slowly
push off to the east along with the main upper level wave this
morning. Snow levels at 4,500ft to 5,000ft can accumulate a few
more inches of snow early this morning(mainly on grassy surfaces).
As the sun comes up, snow levels will rise back to 6,000-7,000ft.
This combined with widespread snow moving out of the area, I`ve
kept the Winter Weather Advisories to expire this morning (6am for
Central/Southwest MT mountains and 12pm for the Northern
Continental Divide). Wind chills will be cold this morning. Lower
elevations is forecasted for wind chills to drop into the 20s-30s
while mountain locations can drop into the teens. Another upper
level disturbance from Canada will push south into the region
this afternoon, producing more scattered to widespread showers. A
few thunderstorms is also expected with showers this afternoon.
These showers can bring up to another 0.1-0.25" of moisture.
Showers will taper down during the evening, ending around
midnight.

Wednesday and Thursday...Northwest flow aloft will transition to
southwest flow aloft over the next few days. The southwest flow
will help bring in warmer air and help moderate temperatures
closer to normal averages. There will be upper air disturbances
passing through that will produce isolated showers/thunderstorms
(primarily across Central/North Central MT). Precipitation amounts
look to be light. The NBM 75th percentile in precipitation
amounts shows the CWA receiving up to a 0.1" of moisture for both
days.

Friday...A small shortwave trough passing through will bring
better chances for scattered/widespread precipitation, primarily
for central and eastern portion of the CWA. There`s a 40-60% from
Central Chouteau, Judith Basin, and Hill Counties and to the east
of receiving 0.25" of precipitation.

Saturday and beyond...By the weekend, temperatures will be well
above normal across the region. We will be monitoring locations
across the CWA reaching 90 degrees for the first time this year on
Sunday. The climatological average for the first 90 degree day of
the year happens on June 23rd for Great Falls and Bozeman, June
26th for Helena, and June 12th for Havre. NBM probabilities are
showing a 50-60% for high temperatures reaching 90 degrees around
the Helena and Bozeman area, and 30% for the Great Falls area. The
beginning of next week brings more low chances for precipitation
daily. -Wilson

&&

.AVIATION...
18/06Z TAF Period

Widespread rain, a rain/snow mix, or snow will gradually exit
eastern portions of Southwest through North Central Montana through
12-18z Tuesday; however, another disturbance pivoting southeast
around the departing one will bring a return chance of showers and
scattered thunderstorms moving from northwest to southeast across
North Central and into portions of Southwest Montana beyond 12z
Tuesday. IFR/MVFR/low-VFR conditions will prevail across all
terminals regardless of falling precipitation, with the lowest and
most persistent CIGS occurring in THE northerly upslope favored
locations of Central and Southwest Montana. Mountain obscuration will
continue across the entirety of the Norther Rockies over the next 24
hours. - Moldan

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

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  59  37  67  41 /  80  50  30   0
CTB  54  31  64  38 /  80  30  30   0
HLN  61  40  72  46 /  70  40  20   0
BZN  55  33  68  39 /  50  50  10   0
WYS  50  25  62  32 /  60  20  10   0
DLN  55  31  66  37 /  40  30   0   0
HVR  60  41  68  45 /  60  50  30   0
LWT  55  34  65  41 /  90  30  40  10

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory until noon MDT today for East Glacier
Park Region-Southern Rocky Mountain Front.

Winter Weather Advisory until 6 AM MDT early this morning for
Big Belt, Bridger and Castle Mountains-Elkhorn and Boulder
Mountains-Gallatin and Madison County Mountains and Centennial
Mountains-Little Belt and Highwood Mountains-Northwest
Beaverhead County-Snowy and Judith Mountains.

&&

$$

http://www.weather.gov/greatfalls