Area Forecast Discussion
Issued by NWS Great Falls, MT

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
FXUS65 KTFX 230932

Area Forecast Discussion
National Weather Service Great Falls MT
332 AM MDT Fri Sep 23 2016


Today through Saturday Morning...Large upper level low is now
currently located across eastern NV and Western UT streaming ample
moisture across the area. This low has dove slightly further south
than models indicated earlier in the week. The result...ID and WY
are getting ample amounts of rain...while MT receives the remnant
moisture in the mainly diffluent flow. With a lack of deep layer
moisture...light rain...drizzle...and some areas of fog will be
the main story for early this morning. All is not lost for rain
enthusiasts. Models do indicate as this low slowly progresses
eastward a bit of energy heads into MT. This will bring us the
best shot for rain today...mainly this morning from south to
north. Rainfall amounts look to be on the moderate side for
today...with new accumulations of 0.1 to 0.5 inches...with some
locally higher amounts across the east and south. With little
instability and reasonable qpf amounts...have removed the hydro
portion of the discuss as flash flooding will be little concern
for today. Caution should still be the ground saturates
local creeks...streams...and rivers may rise. Lower RH at the mid
levels will diminish chances for rain...and perhaps bring a shot
for drizzle...this afternoon across the northern half of the CWA.
Southern areas will be close enough to the upper low that
scattered to numerous showers are possible through the afternoon
and evening hours. Another round of showers could develop tonight
into Saturday morning...however a sharp cutoff will be found as
the low moves across WY. Current thinking is best chances for
precipitation tonight into Saturday morning will be from
Beaverhead county north to easter Cascade County to Hill County
and east from there. The cold air in this system is also lacking.
Snow levels may still get as low as 7000 feet...however...above
8000 feet is more likely...with little impacts expected. Below
normal temps are once again expected today...with highs generally
in the 50s and lows in the 40s for tonight.

Rest of Saturday and Sunday...The large upper low takes an
interesting north and east track bringing NW flow to the region
for the rest of Saturday. This type of cool unsettled flow could
bring a few scattered showers to the region. A developing ridge of
high pressure then begins to push into the region Saturday night
through Sunday. This looks to end precipitation and begin a
warming and dry trend. Saturday`s temps will remain cool in the
50s...with 60s possibly returning for Sunday. Anglin

Sunday night through Friday...Next week will start off with upper
level ridging over the Northern Rocky Mountains. Dry conditions will
prevail Sunday night through Wednesday morning with temperatures
warming to near 70 on Monday and into the upper 70s Tuesday.
Wednesday afternoon through Sunday will see an increasingly moist
west to southwest flow aloft as the ridge is flattened by a weather
system moving through western/central Canada and another trough
develops along the Pacific Northwest Coast. Am expecting to see a
gradual decrease in high temperatures Wednesday through Friday with
isolated/scattered showers possible each day, especially over the
western mountains. mpj


Updated 0600Z.

Overall A mix of MVFR and IFR conditions are expected for tonight
through Friday morning...and possibly into Friday afternoon.
Mountains will remain obscured with perhaps some mountain snow over
much of the next 24 hours. Gradual improvement will then be possible
later in the forecast period. The next round of showers will push up
from the south overnight tonight through Friday morning. Most TAF
sites could see lowering clouds below 1000 feet...and chances for
rain, mist, and drizzle. Some lower visibilities are also possible,
especially in the heavier rain which is currently expected from KLWT
to KHVR. Conditions may slightly improve after 18Z Friday as rain
becomes more scattered. However...a low cloud deck could continue
MVFR and isolated IFR ceilings through Friday afternoon. Sites along
and east of a line from KBZN to KLWT could see more chances for rain
Friday night...with perhaps a few areas of VFR west of this line.


GTF  55  47  58  41 /  90  20  20  20
CTB  58  43  57  39 /  40  10  20  20
HLN  57  43  60  39 /  80  30  20  10
BZN  53  41  57  36 /  80  60  30  10
WEY  50  33  50  30 /  80  80  30  10
DLN  54  38  57  34 /  80  40  20   0
HVR  55  45  60  40 /  80  20  40  20
LWT  51  43  54  38 /  80  50  40  20



$$ is the U.S. government's official web portal to all federal, state and local government web resources and services.