Area Forecast Discussion
Issued by NWS Great Falls, MT
FXUS65 KTFX 170002
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
550 PM MDT Sun Mar 16 2014
Today through Tuesday...An upper level low pressure system over
the Pacific Northwest will approach the Rockies tonight. The
upper level jet will shift south by midnight, dropping farther
south over Southwest Montana by Monday. This will bring a colder
air mass and precipitation into the region as the associated cold
front moves from the Northern Rockies towards Southwest Montana.
Not much precip is expected ahead of the front and a brief period
of light rain may precede mostly snow after frontal passage. The
mountains of the Rocky Mountain Front and Central Montana will
likely see significant snowfall at the upper elevations. The
plains of Central Montana will see a few inches but strong winds
will create difficult conditions in snow and blowing snow. The
Havre area will have the best chance of mixed rain and snow during
the day with all locations south and west likely seeing
accumulating snow. Cold air will continue to move into the region
through the day Monday and max temps will not climb much above the
overnight lows. The system moves through in about 24 hours with
the bulk of moisture moving out of the region by later Tuesday
morning. Some lingering instability may generate a couple
afternoon showers Tuesday but widespread precipitation is not
Tuesday night through Sunday...Some slight drying conditions are
expected through Wednesday as a weak ridge builds back into the
area. Another round of moisture will move in late Wednesday night
as a shortwave moves across the state. Northwest flow aloft and
occasional shortwave energy will combine with ample Pacific moisture
to bring a chance for light snow showers through the remainder of
the long term forecast. Models continue to show slight differences
over timing of these weak disturbances...however confidence in a
cool and occasionally snowy extended period continues to increase.
Gusty winds will continue along the Rocky Mountain Front and
adjacent plains this evening before tapering after sunset. VFR
conditions will prevail for the next 8 to 12 hours, then deteriorate
from north to south beginning late tonight along the Rocky Mountain
Front spreading into north-central and southwest Montana through
Monday as a cold front pushes through the region. Precipitation will
start as a mix of rain and snow at TAF sites before changing to all
snow between 15z and 18z Monday. Winds will also become northerly
with gusts up to 30kts, which will create low visibility in snow and
blowing snow. Periods of MVFR and IFR CIGS/VIS are likely in areas
of snow and mountains will become obscured. MLV
Warm temperatures are forecast for today and the risk for ice
jams over Southwest Montana will continue. Cooler air will move
back into the area Monday along with rain and snow.
.PRELIMINARY POINT TEMPS/POPS...
GTF 36 39 24 40 / 10 100 60 20
CTB 31 38 22 39 / 40 100 50 20
HLN 36 41 26 41 / 10 100 60 10
BZN 32 41 23 38 / 10 100 70 40
WEY 26 35 12 33 / 10 90 70 20
DLN 32 36 18 34 / 10 80 60 10
HVR 36 46 27 44 / 20 100 50 40
LWT 36 41 24 37 / 10 100 80 40
WINTER STORM WARNING from Midnight tonight to 6 AM MDT Tuesday FOR
ELEVATIONS ABOVE 5000 FEET FOR Northern Rocky Mountain
Front...Southern Rocky Mountain Front.
WINTER WEATHER ADVISORY from 6 AM Monday to 6 AM MDT Tuesday
Blaine...Broadwater...Cascade...Central and Southern Lewis and
Clark...Chouteau...Eastern Glacier...Eastern Pondera...Eastern
Liberty...Madison...Meagher...Northern Rocky Mountain Front...
Southern Rocky Mountain Front...Toole.
HIGH WIND WARNING until 9 PM MDT this evening Eastern Glacier...
Eastern Pondera...Eastern Teton...Liberty...Northern Rocky
Mountain Front...Southern Rocky Mountain Front...Toole.
FLOOD ADVISORY until Monday afternoon for Jefferson.