Area Forecast Discussion
Issued by NWS Missoula, MT
FXUS65 KMSO 031031
Area Forecast Discussion
National Weather Service Missoula MT
431 AM MDT MON AUG 3 2015
.DISCUSSION...One more day of well above normal temperatures and
smokey skies before a surge of monsoonal moisture ushers in a
pattern change. This afternoon, clouds will increase with
scattered thunderstorms developing in north central Idaho and
pushing northward through the evening. These will remain primarily
south of the I-90 corridor, but a few storms could also develop
along the Continental Divide. Gusty winds and lightning will be
the main threat with these storms. Overnight into Tuesday morning,
a weak front will bring showers and breezy winds through the rest
of northwest Montana.
Tuesday will be cooler with western Montana back to more seasonal
temperatures. North central Idaho will also cool a few degrees,
but not as drastically as western Montana. Scattered afternoon
thunderstorms with again be possible over much of western Montana.
On Wednesday, another shot of moisture will bring more widespread
showers and thunderstorms over southwest Montana and north central
Idaho. Drier air will limit showers for northwest montana.
Relatively dry westerly flow aloft will develop over the Northern
Rockies Thursday through at least midday Saturday. Daytime
temperatures will trend upward somewhat. Breezy afternoons are
probably the most significant weather impact for this time.
Long-range models suggest another surge of moisture over the
Northern Rockies midday Saturday through the remainder of the next
weekend, with showers and thunderstorms plausible. Northwest
Montana appears to, once again, be largely missed by this next
opportunity for precipitation over the region.
.AVIATION....Light terrain driven winds will be present through
the morning, with wildfire smoke continuing to cause minor
reductions in visibility at times. By the afternoon, scattered
mid- level clouds will begin making their way north over southwest
Montana and Lehmi county as moisture increases. Smoke
concentrations will begin to dissipate during this transition.
KSMN could see some vicinity showers and thunderstorms during the
afternoon, with these storms spreading north to KBTM by the
evening. As a front moves through overnight into Tuesday morning,
KMSO and KGPI will also have a chance for a couple hours of
vicinity showers. Winds will be gusty with any thunderstorm, and
with the frontal passage.