Area Forecast Discussion
Issued by NWS Great Falls, MT

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FXUS65 KTFX 100939
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
339 AM MDT Thu Jul 10 2014

.DISCUSSION...

Today through Saturday...Water vapor shows a shortwave to our east
with dry air to the west. The flow aloft will remain zonal as
another shortwave moves over the West Coast late this evening. A
weak cold front will move through the zones this morning and
temperatures will be slightly cooler today, mostly to the north.
Weak afternoon instability will develop today but any thunderstorm
activity will generally be isolated. A weak disturbance in Canada
will move towards the Hiline tonight and surface high pressure in
Alberta will move south. Low level winds will strengthen and shift
to the northeast during the night as this high moves into the
region. Instability Friday afternoon will be supported by a
shortwave crossing the Rockies. Best instability will be over
Gallatin through Meagher Counties. Will also have some good shear as
the cool air boundary pushes south which and this will increase the
chance for a strong or severe thunderstorm. Convection should not
move into the northern zones where the cooler air mass should
inhibit convection. High pressure will build aloft Saturday but
some moisture will be available underneath the ridge, mainly across
the southwest zones. The central zones look to be the most unstable
Saturday afternoon and convection should begin over the southwest
and move north.  Forecasted soundings look good for strong outflow
gusts as well. Zelzer

Saturday night through Thursday...An upper level ridge high
pressure will be over the region this weekend...then the upper level
ridge will shift westward on Monday...as a fairly strong upper level
low pressure over the Great Lakes area rotates a bit cooler air into
the region. As the upper level low over the Great Lakes begins to
move eastward on Tuesday...the upper level ridge will also start to
shift back eastward for Tuesday afternoon through Thursday. Thus
fairly warm temperatures are expected for Sunday...then seasonable
temperatures for Monday and Tuesday...with a return to slightly
above normal temperatures for Wednesday and Thursday. In terms of
precipitation...confidence is quite low on any one given day...thus
most days the chances for thunderstorms are fairly isolated. The
best time frame for any storms to occur will be late afternoon
through around Midnight...but again the thunderstorm activity should
be fairly isolated and not have significant impacts on any one given
day. Brusda

&&

.AVIATION...
UPDATED 0500Z.
VFR conditions are expected to continue across the area at least
through Thursday evening. Clouds and showers will continue to
diminish through 10Z across central Montana as a disturbance moves
through the area. A weak cold front will accompany the disturbance,
shifting the southwesterly winds more northwesterly from northwest
to southeast over the central Montana plains between 09Z and 15Z.
Clouds will then increase again after 18Z as the mid level flow
becomes more northwesterly and brings moisture into the area from
Canada. Surface winds will decrease during this time and there will
be a chance of showers along the Canadian border.
Coulston

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  87  55  79  55 /  10  20  10  10
CTB  80  51  76  50 /  10  20  10  10
HLN  91  57  84  58 /  10  10  10  20
BZN  87  53  84  53 /  10  10  30  20
WEY  78  43  79  44 /  40  30  50  40
DLN  86  53  85  56 /  10  10  20  20
HVR  87  55  80  54 /  10  20  20  10
LWT  86  53  78  52 /  10  20  20  20

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

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