589
FXUS65 KMSO 121759
AFDMSO

Area Forecast Discussion
National Weather Service Missoula MT
1159 AM MDT Mon Aug 12 2024

.DISCUSSION...A broad trough remains over the Northern Rockies,
temperatures will remain at or a few degrees below normal through
Wednesday. Of interest a few disturbances will rotate through the
trough. The first this afternoon will bring the potential for
strong storms, mainly over southwest MT. A relatively dry lower
atmosphere combined with wind shear of 45 to 55 mph could produce
surface outflow wind gusts 40 to 50 mph.

The second disturbance Tuesday morning and afternoon will have
elevated atmospheric moisture of 2 times the climatological norm
centered over west-central MT and the Clearwater Mountains of ID.
While very heavy downpours will be possible with 1-hr
precipitation rates 0.25 to 0.50 inch in the strongest storms. The
limitation on strong storms developing would be cloud cover in
association with anomalous moisture and morning convection
producing stable valleys.

Flat zonal flow develops Wednesday with a general summer thunderstorm
threat, mainly south and east of Missoula.

Thursday into the weekend, a Pacific trough deepens along the
coast. The models are almost 100% in agreement this feature
develops. There is variance within the model members in the
strength of the trough and eastward extent. A pattern such as this
is typical of thunderstorm development, potentially strong,
Questions remain on moisture availability after Saturday evening,
which could decrease thunderstorm coverage.

&&

.AVIATION...A subtle disturbance will move through the region
today causing scattered rain showers with the potential of
thunderstorms. This afternoon the atmosphere becomes unstable
enough to produce isolated convection throughout the region. KBTM
between 13/0100 and 13/0200z is the terminal with the highest
probability (20% or less) of receiving a stronger storm with
outflow gusts 30 to 40 mph.

&&

.MSO WATCHES/WARNINGS/ADVISORIES...
MT...None.
ID...&&

$$