Flash Flood Warning 8, NWS Boise, ID

Area Forecast Discussion
National Weather Service Boise ID
224 PM MDT Thu Aug 3 2023

.SHORT TERM...Tonight through Saturday night...A weak upper level
trough will remain nearly overhead tonight, increasing the chance
for thunderstorms to continue through the overnight hours. As this
moves away Friday morning, we will have a relative minimum in
convective activity until mid-afternoon. By late afternoon,
thunderstorms will again develop, especially in the mountains of
central Idaho and in southeast Oregon. Some strong storms are
possible. These storms will move generally north and out of the area
by Saturday morning, but overnight thunderstorms are again possible -
most notably in Harney County. On Saturday, thunderstorms will
be mainly in the north, but with a still-worth-mentioning-chance
(5-25%) in the south. Temperatures will be a few degrees below
normal each day due to extensive cloud cover. Wind gusts from
thunderstorms could approach 50 mph, with 30-40 mph likely in
many areas. The best chance for these outflows is over southeast
Oregon.

.LONG TERM...Sunday through Thursday...Occasional upper level
systems will move through generally westerly flow through the long
term. Operational runs differ on timing, as usual. However, there is
high confidence that the first one will move through Sunday,
bringing showers and thunderstorms mainly across the north. After
that, several more will move through but they are expected to be
fairly weak. Each one will bring a small increase in wind and also
an increase in the chance of showers and thunderstorms. Temperatures
will be slightly below normal through at least Thursday. In fact
there is a less than 5% chance of reaching 100 degrees anywhere in
the area through Thursday.

&&

.AVIATION...Mainly VFR. Scattered to numerous showers and
thunderstorms will continue through the night. Smoke will reduce
visibility to MVFR at times near wildfires. Surface winds outside of
storms: mainly east to southeast 5-15 kt, except winds becoming NW-
NE 5-12 kt in the Treasure Valley after 03/18Z. Gusty outflow winds
to 25-40 kt and locally heavy showers possible with thunderstorms.
Winds aloft at 10kft MSL: variable 5-15 kt.

Weekend Outlook...Mainly VFR. Afternoon showers and thunderstorms
Friday through Sunday, with highest coverage expected on Friday.
Thunderstorms will be capable of outflow wind gusts to 25-40 kt and
local heavy rainfall. Smoke will reduce visibility near active
wildfires. Breezy afternoon surface winds each day, mainly W to NW
10-25 kt.

&&

.BOI WATCHES/WARNINGS/ADVISORIES...
ID...Red Flag Warning until midnight MDT tonight IDZ400-420-424-426.
     Red Flag Warning until 11 PM MDT Friday IDZ423.
OR...Red Flag Warning until 11 PM MDT /10 PM PDT/ Friday
     ORZ636-637-646.

&&

www.weather.gov/Boise
www.facebook.com/NWSBoise
www.twitter.com/NWSBoise

SHORT TERM...SP
LONG TERM....SP
AVIATION.....SP

Preliminary Local Storm Report
National Weather Service Boise ID
129 PM MDT Thu Aug 3 2023

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0625 PM     Flash Flood      1 NE Featherville       43.61N 115.26W
08/02/2023                   Elmore             ID   Trained Spotter

            Station Elevation: 4546 ft.

&&

WH