Area Forecast Discussion
Issued by NWS Great Falls, MT

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FXUS65 KTFX 020407
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
907 PM MST Sun Mar 1 2015

.UPDATE...

No updates to going forecast tonight. Looks like only increasing
high cloudiness tonight before the system moves into the area on
Monday. Southerly winds will become breezy overnight, keeping
temperatures from falling as much as last night. Only made an
adjustment to hourly winds to better reflect current trends.
Coulston

&&

.AVIATION...
UPDATED 0015Z.
High clouds will increase across the area overnight as a disturbance
aloft approaches Montana from the west. A strong cold front will
move south out of Canada and across the area after 18z. Widespread
snow and gusty north winds will accompany the front. VFR conditions
prevail with widespread MVFR/IFR conditions developing after 18z due
to low ceilings, snow, and blowing snow. Mountains becoming obscured
after 18z as well.

&&

.PREV DISCUSSION...
/ISSUED 515 PM MST Sun Mar 1 2015/

Tonight through Tuesday...Cloud cover will increase overnight but
generally quiet weather will continue through the early morning
hours. However, mid to late Monday morning will see a strong
surface cold front sweeping southward through central Montana,
reaching southwest Montana by Monday evening. Winds will shift to
the north and increase behind the front with temperatures expected
to drop through the day behind the frontal boundary. Widespread
snow and blowing snow will accompany the frontal passage with
anywhere from 1 to 4 inches of snow accumulation expected by
Tuesday morning over the plains and in the valleys. Mountain
locations will likely see anywhere from 3 to 8 inches with some of
the higher peaks in Glacier Park possibly seeing up to 10 inches.
Very cold conditions will prevail Monday night and Tuesday.
Overnight lows are expected to drop to near 10 below zero in the
north and the single digits above zero in the southwest. Tuesday`s
highs will only climb into the single digits above zero in the
north and the teens in the far southwest valleys. Additionally,
breezy to windy conditions are expected Monday night and Tuesday,
allowing wind chill values to drop as much as 20 to 30 degrees
below zero. I anticipate that Wind Chill Advisories will be issued
for this time period. mpj

Tuesday night through Sunday...The upper level low pressure trof
will move east of the zones Tuesday night, high pressure will build
aloft, and the airmass will dry. This will lead to an end of
precipitation and clearing skies. At lower levels, the surface high
pressure will be over Central Montana and, with the clearing skies,
cold overnight low temps are expected. Some dangerous wind chills
are thus expected across the region. The surface high will be moving
east Wednesday and temperatures will begin to trend upwards. With a
high pressure ridge building over the West Coast, Central Montana
will be underneath northwest flow aloft. A disturbance moving
through this flow will bring some increased cloud cover to the area
and strengthen a surface trof along the lee of the Rockies. Brisk
winds along the slopes of the Rockies will result. Southwest flow
across the Rockies will also hasten the warming across western
portions of the region. A shortwave will move across the West Coast
Thursday and flatten the ridge. Moisture ahead of this system will
cross the Rockies late Thursday and bring a chance of precipitation
across the region. This shortwave will also strengthen winds and
breezy conditions will continue over the Rockies. The shortwave will
move east of the Rockies Friday and the airmass will dry again
Friday night. High pressure will build again through Saturday but
another shortwave will move through the Pacific Northwest Saturday
night. This will bring another chance of precipitation to the area
Saturday night and Sunday but any snow accumulations should remain
low and at higher elevations. Temps will begin the period below
normals Tuesday night and Wednesday but rise to near and above
normals Thursday. Temps will remain moderate through the end of the
period. Zelzer

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  16  29  -5   7 /   0 100  90  20
CTB  14  22  -7   5 /  10 100  30  10
HLN  14  32   3  14 /   0  80 100  30
BZN   9  34   1  14 /   0  30 100  40
WEY   1  33  -5  15 /   0  20  70  40
DLN   9  38   2  17 /   0  20 100  30
HVR  13  28  -4   5 /   0  80  30  20
LWT  11  31  -5   5 /   0 100  90  30

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY from 5 PM Monday to 11 AM MST Tuesday
Beaverhead...Broadwater...Gallatin...Jefferson...Madison...
Meagher.

WINTER WEATHER ADVISORY from 11 AM Monday to 5 AM MST Tuesday
Cascade...Central and Southern Lewis and Clark...Chouteau...
Eastern Teton...Fergus...Judith Basin...Southern Rocky Mountain
Front.

WINTER WEATHER ADVISORY from 5 AM Monday to 5 AM MST Tuesday
Eastern Glacier...Eastern Pondera...Northern Rocky Mountain
Front...Toole.

&&

$$

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