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 251546

Area Forecast Discussion
National Weather Service Great Falls MT
945 AM MDT Sun Sep 25 2016


Most of forecast appears valid. Only adjustment was to modify
temperature trends in the West Yellowstone area per latest obs and
model guidance. Highs late this afternoon will be near-normal and
reach the 60`s in most locations. Skies will be mainly clear to
partly cloudy as some mid- to upper-level cloud cover spills over
the high pressure ridge building into our area. Jaszka


/ISSUED 525 AM MDT Sun Sep 25 2016/

Today through Tuesday...Recent large upper low has moved into the
Dakotas this morning. Ridge of high pressure is beginning to
build across the western US...with weak nw flow across our region.
Todays nw flow pattern will be different than your typical nw warmer temperatures move in aloft. The result will be
weak to little instability...and mainly dry conditions. Some mid
to upper level moisture will find its way across the region
throughout today...bringing some mid to high level clouds at
times. Breezy winds may also be possible this afternoon...but
still far below high wind criteria. High pressure further builds
across the western us tonight through Monday. This will push out
the the mid level moisture...and bring dry and warm air across
the region. With the top of the ridge to our south and west...a
continued west to northwest flow will be found aloft. This quick
flow at times could continue breezy winds...especially across the
Rocky Mountain Front and northern half of the CWA. High pressure
pushes east into the CO/WY area for Tuesday. This results in a
slight break down of the ridge for us...and further enhances the
westerly flow. Dry conditions are still expected to
continue...however...breezy to gusty winds may return to the
CWA...with the Rocky Mountain Front and northern portions finding
the highest winds. Current thinking is winds will still remain
below high wind criteria. Some gusts along the Rocky Mountain
Front may approach 50+ MPH at times. With windy...warming...and
drying conditions...some minor elevated fire weather concerns
will be found during the short term. Recent rains have placed area
fuels in the low to moderate danger categories...limiting high
fire danger potential. Other story line to start the week will be
the mentioned warming trend. Temperatures today will warm into the
mid 60s...with 70s for Monday...and perhaps the return of 80s for
Tuesday. Many areas haven`t seen 80s since earlier this month.

Tuesday night through Sunday...Medium range models are in decent
agreement for Tuesday night through Friday but solutions diverge for
next weekend. The forecast period starts off with remnants of a
flattened shortwave ridge edging eastward from Montana into the
Dakotas. Meanwhile, an upper level low develops off the British
Columbia coast which gradually elongates into a trough along the
Pacific Northwest coast with flow aloft over Montana backing to the
south-southwest and becoming increasingly moist. Tuesday night
through Thursday will remain dry for most locations with seasonable
temperatures expected each day. Isolated mountain showers develop
near Glacier Park Wednesday then expand across all the western
mountains on Thursday with a few showers or thunderstorms possibly
moving out over the plains Thursday evening. Showers and possible
thunderstorms increase in coverage across the entire forecast area
Friday through Sunday with a surface cold front expected to move
through the region for cooler temperatures for next weekend. mpj


Updated 1125Z.

Mostly clear to partly cloudy skies, generally light winds, and
widespread VFR conditions will prevail through early Monday morning.
Westerly winds could become locally breezy from 16Z Sunday through
01Z Monday but they will diminish again by mid-evening. mpj


GTF  68  44  76  50 /   0   0   0   0
CTB  67  41  75  46 /   0   0   0   0
HLN  69  42  77  47 /   0   0   0   0
BZN  66  42  75  46 /   0   0   0   0
WEY  60  29  68  36 /   0   0   0   0
DLN  67  39  73  43 /   0   0   0   0
HVR  67  43  74  48 /  10   0   0   0
LWT  64  44  73  51 /  10   0   0   0



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