Scientific Forecaster Discussion
fxus65 kmso 280933
Area forecast discussion
National Weather Service Missoula Montana
333 am MDT Fri Jul 28 2017
Discussion...another very warm and mostly dry day is expected for
most areas. One exception will be a weak disturbance working from
north- central Idaho into west-central/southwest Montana (mainly
south of Hwy 12) this afternoon and evening which will lead to
isolated showers and thunderstorms. The higher terrain stands the
best chance of seeing a brief thunderstorm, lesser so in the
valleys. Typical threats include brief heavy rain, gusty winds,
and occasional lightning strikes.
Warm high pressure will intensify over the northern rockies this
weekend and continue to be present through at least next week.
Afternoon temperatures will be a bit warmer than recent days, with
most low elevations in the 90-100 degree range. Residual moisture
beneath the high pressure may introduce a few afternoon/evening
thunderstorms across southwest Montana each day Saturday through
Tuesday next week. Cloud-to-ground lightning and brief, gusty
winds will be the main impact of any storm that develops, however
little to no beneficial rainfall is anticipated.
Long-range weather models suggest that a slight pattern change may
occur next weekend, however the change may amount to temperatures
merely cooling to near the seasonal average and minimal chances
of beneficial rainfall.
Aviation...VFR conditions will be present across the region
through the early afternoon hours, aside from patchy smoke from
area wildfires which could limit visibility for localized areas. A
weak disturbance and daytime heating will work on mid level
moisture to produced isolated thunderstorms mainly south of a line
from Lowell, Idaho to MacDonald Pass. Ksmn and kbtm will have a
chance of vicinity thunder between 28/2100z and 29/0200z, while
kmso will have a very slight chance. The main threats from
thunderstorms will be gusty winds to 30kt, along with a brief
reduction in visibility due to heavy rain. Shower activity will
diminish during the late evening hours.