Area Forecast Discussion
Issued by NWS Missoula, MT
FXUS65 KMSO 061030
Area Forecast Discussion
National Weather Service Missoula MT
430 AM MDT MON JUL 6 2015
Today will be a mostly benign weather day in comparison to recent
days as drier air has moved into much of the Northern Rockies and
pressure gradients have relaxed, allowing winds to decrease.
Pleasant, quiet weather is in store for most areas today, with
the exception being a few showers and thunderstorms from around
Lemhi County northeastward to the Butte vicinity. Any storms that
pop up will not be very strong, with lightning and brief heavy
rain as the main threats. Temperatures will rebound a bit for
western Montana after yesterday`s cold front, rising to close to
normal for this time of year.
The next weather disturbance will slide into northwest Montana
tonight (along a similar track to yesterday`s system). We`re
expecting some light showers Tuesday morning from Thompson Falls
to Glacier NP. As the trough axis approaches Tuesday afternoon,
instability will increase across western Montana, especially in
the Glacier NP area. Atmospheric moisture will be on the rise as
well. This will lead to a chance of thunderstorms across much the
area, mostly in the afternoon and evening near the Continental
Divide. The main threats with storms would be lightning and heavy
rain. Given the extremely dry fuels across northwest Montana,
there is some concern of fire starts, although the wet nature of
these storms may be able to mitigate. We will be keeping a close
eye on this situation. The biggest difference with this
disturbance versus the last one is the winds in advance of it look
to be weaker.
Another backdoor cool front will push across western Montana on
the backside of the trough Tuesday night. However, this front does
not look as strong as the recent one, both in terms of temperature
change and winds. As before, the cooling effects of the front
will fail to reach parts of central Idaho as the front is expected
to stall just west of the MT/ID border.
Wednesday and Thursday...
Temperatures will gradually begin to warm on Wednesday as the
trough exits the region. Thursday looks to be the warmest day with
highs in the low 90s for many areas. Scattered thunderstorms will
develop during the afternoons, but should mainly be along and
south of I-90.
Beginning Friday, a trough is expected to start deepening off the
West Coast. This will allow moisture to move up from the south and
will lead to a more active thunderstorm pattern through the
.AVIATION...East winds may be breezy at times again for KMSO/KGPI
today, but will be significantly reduced in comparison to
yesterday (more in the 10-15 kt range). Low clouds will affect
KBTM through mid-morning, with ceilings lowering into the 2000 ft
AGL range. KSMN could see a shower or thunderstorm in the
afternoon, with an outside chance at KBTM as well.