Special Weather Statement, NWS Missoula, MT

Area Forecast Discussion
National Weather Service Missoula MT
147 PM MDT Sat Aug 21 2021

.DISCUSSION...The low pressure system that brought us the rain
this morning will bring the region thunderstorms this afternoon
and evening. Ensemble models spread the storms out across the
region from southern Lemhi County, Idaho all the way north through
Glacier National Park and Troy, Montana. Severe weather isn't
expect with these storms, but they are expected to be very wet.
The potential for moderate to heavy rain over recent burn scars is
a concern for potential flash floods or debris flows. We'll be
watching the radar closely this evening for the conditions that
could lead to exactly that.

The rest of the week things dry out as the weather pattern remains
active. We're not expecting much more in the way of rain, but the
region will stay cool and breezy. For the first part of the week,
temperatures will remain below average, and then rise up to near
average late next week. Also, average temperatures for this time
of year in western Montana are in the upper 70s and low 80s as we
quickly approach meteorological Fall in September.

&&

.AVIATION...Thunderstorms moving through the region this afternoon
will dissipate quickly after sunset. Some mid clouds will linger
into the evening, and then clearing overnight will allow some
shallow, patchy fog to form across the region. Fog will mainly
affect along the rivers and while it will be visible from the
terminals it is not expected to directly affect them in the
morning.

&&

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

Special Weather Statement
National Weather Service Missoula MT
458 PM MDT Sat Aug 21 2021

IDZ009-010-MTZ005-006-212330-
Eastern Lemhi County ID-Western Lemhi County ID-
Bitterroot/Sapphire Mountains MT-Missoula/Bitterroot Valleys MT-
458 PM MDT Sat Aug 21 2021

...Strong thunderstorms will impact portions of northwestern Lemhi,
central Ravalli and southwestern Granite Counties through 530 PM
MDT...

At 457 PM MDT, Doppler radar was tracking strong thunderstorms along
a line extending from near Hamilton to 24 miles west of Gibbonsville.
Movement was northeast at 30 mph.

HAZARD...Winds in excess of 30 mph.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects.

Locations impacted include...
Darby, Conner, Sula, Lost Trail Pass and Skalkaho Pass.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

These storms may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.

&&

LAT...LON 4661 11352 4578 11386 4578 11387 4575 11391
      4567 11393 4546 11453 4621 11408
TIME...MOT...LOC 2257Z 231DEG 27KT 4618 11408 4563 11442

MAX HAIL SIZE...0.00 IN
MAX WIND GUST...30 MPH

Special Weather Statement
National Weather Service Missoula MT
551 PM MDT Sat Aug 21 2021

MTZ006-007-220030-
Bitterroot/Sapphire Mountains MT-Butte/Blackfoot Region MT-
551 PM MDT Sat Aug 21 2021

...Strong thunderstorms will impact portions of northeastern Granite
and central Powell Counties through 630 PM MDT...

At 550 PM MDT, Doppler radar was tracking strong thunderstorms along
a line extending from 11 miles south of Ovando to 10 miles north of
Philipsburg. Movement was northeast at 20 mph.

HAZARD...Winds in excess of 30 mph and very heavy rain.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects.

Locations impacted include...
Drummond, Maxville, Jens, Hall, Helmville and New Chicago.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

These storms may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.

&&

LAT...LON 4644 11302 4642 11350 4691 11321 4713 11280
      4687 11279
TIME...MOT...LOC 2350Z 229DEG 17KT 4687 11311 4648 11335

MAX HAIL SIZE...0.00 IN
MAX WIND GUST...30 MPH