156
FXUS65 KTFX 060944
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
344 AM MDT Thu Jun 6 2024

.SYNOPSIS...

Mainly sunny, warm and dry conditions with relatively light winds
are expected today as upper level high pressure strengthens south
and west of the area. Near to above seasonal average temperatures
and dry conditions will persist through most of the weekend with
shower and thunderstorms chances increasing late Sunday with the
arrival of weak weather system.

&&

.DISCUSSION...

The Northern Rockies and MT remain on the northern periphery of a
building upper level ridge centered over the SW US with mainly clear
skies, relatively light winds and warmer temperatures expected
across the region today beneath a westerly flow aloft.

A shortwave disturbance approaching the BC coast will track inland
and across the southern Canadian Prairies tonight, sending a weak
surface front and Canadian airmass south across north-central MT on
Friday while the upper level ridge axis shifts west to a position
along the west coast. Some showers may clip areas near the
US/Canadian border early Friday, but the main affect will be to
knock temperatures back to seasonal averages across north-central MT
with less noticeable cooling across SW MT. Except for some isolated
(<20% chance) terrain generated afternoon convection near the ID
border, most of the area will continue to see dry conditions through
Saturday with a reinforcement of the Canadian airmass keeping
temperatures near seasonal averages on the plains while SW MT
locations hold with temperatures around 5-7 degrees above seasonal
averages.

The upper level ridge axis shifts inland late this weekend but is
suppressed by shortwave energy moving over the top and across the
Northern Rockies late Sunday into Monday. Moisture circulating
around the ridge will be in place with the arrival of the Pacific
disturbance for shower and thunderstorm development late Sunday
across western and southwest MT that would track northeast across
central and north-central MT Sunday night with additional showers
possible on Monday as another weak disturbance slides across the
area. While instability/moisture profiles late Sunday look fairly
weak at this time, winds aloft would provide enough shear for some
stronger thunderstorm potential that will continue to be monitored.

Medium range model ensembles are in reasonable agreement to
rebuild/shift the upper ridge inland again again by the middle of
next week before diverging some with its evolution thereafter.
This would support the expansion of above average temperatures
over much of the area by the middle of next week with generally
dry weather again until late next week. Hoenisch

&&

.AVIATION...

06/06Z TAF Period

VFR conditions, generally light winds, and a few high clouds will
prevail for all sites through the TAF period. -thor

Refer to weather.gov/zlc for more detailed regional aviation
weather and hazard information.

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  80  49  72  47 /   0   0   0   0
CTB  75  46  69  44 /   0  10   0   0
HLN  85  54  82  53 /   0   0   0   0
BZN  83  49  82  48 /   0   0   0   0
WYS  77  46  77  43 /  10  20  20  10
DLN  83  51  84  50 /   0   0  10   0
HVR  77  49  72  48 /   0  10   0   0
LWT  74  47  70  45 /   0   0   0   0

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$

http://www.weather.gov/greatfalls