Special Weather Statement, NWS Missoula, MT

Area Forecast Discussion
National Weather Service Missoula MT
233 PM MDT Sat Aug 5 2023

.DISCUSSION...Light to moderate rain has been falling throughout
the day, mainly for areas along and south of the I-90 corridor in
western Montana. Wetting rains have been reported as far north as
Arlee in the southern Mission Valley. This precipitation shield
will slowly progress north and west through the afternoon as the
surface low begins spinning up in eastern Washington. Partial
clearing south of the precipitation shield will open the door for
the development of scattered thunderstorms this afternoon,
starting around 3PM MDT and continuing through the evening hours.
Areas with the best chance in seeing thunderstorms will be
locations along and south of I-90 in western Montana and north-
central Idaho. Occasional lightning and heavy rainfall will be the
main hazards from any convective activity.

Localized increase in easterly winds are expected this evening and
overnight along highway 93 in the Mission Valley and Flathead
Lake. Wind gusts as high as 25 mph are expected in these areas.
Take precautions if you have plans to be on the Lake.

The surface low will be slow to move out of the region, resulting
in a second surge of moisture being transported west out of the
Central Plains on Sunday. Much like today, expect light to
moderate rainfall in much the same areas in the morning, with
scattered thunderstorms in the afternoon and evening.
Probabilities for rainfall totals reaching a 0.25" or more for
today and Sunday remain around 35-45%. Chances for a wetting rain
(>0.10") for the same period is at 80% or higher. Areas that have
the least chances of receiving a wetting rain will be locations
north of Flathead Lake to Glacier National Park.

Temperatures this weekend going to into early next week, will be
around 10 to 15 degrees below normal for this time of year.
Rainshowers will also remain in the forecast going through at
least Wednesday next week.

&&

.AVIATION...Light to moderate rainfall will continue through the
afternoon for aviation sites along and south of the I-90 Corridor.
Scattered thunderstorms are still possible in these same areas
this afternoon and evening, with a 50-60% probability. Northwest
Montana, in the vicinity of KGPI will have lesser chances with a
30-35% probability. Due to the recent moisture and expected light
winds, patchy morning fog is possible in the vicinity of KMSO and
KHRF tomorrow morning.

&&

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

Special Weather Statement
National Weather Service Missoula MT
530 PM PDT Sat Aug 5 2023

IDZ006-007-060115-
Southern Clearwater Mountains ID-Orofino/Grangeville Region ID-
530 PM PDT Sat Aug 5 2023

...Strong thunderstorms will impact portions of north central Idaho
and southwestern Clearwater Counties through 615 PM PDT...

At 530 PM PDT, Doppler radar was tracking strong thunderstorms along
a line extending from 10 miles southeast of Kooskia to near Nezperce.
Movement was northeast at 15 mph.

HAZARD...Winds in excess of 40 mph and pea size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

Locations impacted include...
Kooskia, East Kamiah, Stites, Winona, Glenwood, Greer, Syringa,
Pardee, and Woodland.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Torrential rainfall is also occurring with these storms and may lead
to localized flooding. Do not drive your vehicle through flooded
roadways.

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 4616 11623 4616 11622 4615 11620 4618 11618
      4621 11615 4621 11606 4623 11601 4629 11612
      4638 11618 4640 11618 4619 11561 4601 11579
      4613 11624
TIME...MOT...LOC 0030Z 205DEG 14KT 4605 11581 4619 11616

MAX HAIL SIZE...0.25 IN
MAX WIND GUST...40 MPH