WWA Summary for Flash Flood Watch Issued by BOI

Flash Flood Watch

Flood Watch
National Weather Service Boise ID
1230 PM PDT Tue Aug 26 2025

.A surge of deep monsoonal moisture combined with a slow-moving
upper trough will bring periods of heavy showers and thunderstorms
across the region. This airmass contains anomalously high moisture
content, supporting the potential for excessive rainfall. Flash
flooding will be possible, especially in steep terrain, narrow
canyons, and near recent burn scars where soils are less able to
absorb rainfall. The greatest risk will be Tuesday afternoon through
Wednesday evening as repeated rounds of storms move through.

IDZ011>016-028>030-033-ORZ062>064-272000-
/O.CON.KBOI.FF.A.0005.000000T0000Z-250828T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
West Central Mountains-Lower Treasure Valley-Boise Mountains-
Upper Treasure Valley-Southwest Highlands-Western Magic Valley-
Camas Prairie-Owyhee Mountains-Southern Twin  Falls County-Upper
Weiser River-Baker County-Malheur County-Oregon Lower Treasure
Valley-
Including the cities of Silver City, McCall, Big Creek,
Hollister, Glendale, Ontario, Mesa, Cuprum, Nyssa, Caldwell,
Soldier, Ola, Murphy Hot Springs, Hill City, Fruitvale,
Fairfield, Grasmere, Nampa, Cambridge, Riddle, Council, Warm
Lake, Baker, Malheur City, Rogerson, Prairie, Indian Valley,
Anderson Dam, Selby, Goodrich, Reynolds, Blaine, Corral, Bear,
Three Creek, Cascade, Twin Falls, Boise, and Pine
130 PM MDT Tue Aug 26 2025 /1230 PM PDT Tue Aug 26 2025/

...FLASH FLOOD WATCH REMAINS IN EFFECT THROUGH WEDNESDAY EVENING...

* WHAT...Flash flooding caused by excessive rainfall continues to be
  possible.

* WHERE...Portions of Idaho, including the following areas, Boise
  Mountains, Camas Prairie, Lower Treasure Valley, Owyhee Mountains,
  Southern Twin  Falls County, Southwest Highlands, Upper Treasure
  Valley, Upper Weiser River, West Central Mountains and Western
  Magic Valley and Oregon, including the following areas, Baker
  County, Malheur County and Oregon Lower Treasure Valley.

* WHEN...Through Wednesday evening.

* IMPACTS...Heavy rainfall could trigger flash flooding or debris
  flows, especially in and near recent wildfire burn scars.

* ADDITIONAL DETAILS...
  - https://www.weather.gov/safety/flood

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action
should Flash Flood Warnings be issued.

&&

$$

TL

Flood Watch
National Weather Service Boise ID
1230 PM PDT Tue Aug 26 2025

.A surge of deep monsoonal moisture combined with a slow-moving
upper trough will bring periods of heavy showers and thunderstorms
across the region. This airmass contains anomalously high moisture
content, supporting the potential for excessive rainfall. Flash
flooding will be possible, especially in steep terrain, narrow
canyons, and near recent burn scars where soils are less able to
absorb rainfall. The greatest risk will be Tuesday afternoon through
Wednesday evening as repeated rounds of storms move through.

ORZ061-271200-
/O.EXT.KBOI.FF.A.0005.000000T0000Z-250827T1200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Harney County-
Including the cities of Venator, Dunnean, Diamond, Crane,
Buchanan, New Princeton, and Burns
1230 PM PDT Tue Aug 26 2025

...FLASH FLOOD WATCH NOW IN EFFECT THROUGH LATE TONIGHT...

* WHAT...Flash flooding caused by excessive rainfall continues to be
  possible.

* WHERE...A portion of southeast Oregon, including the following
  county, Harney County.

* WHEN...Through late tonight.

* IMPACTS...Heavy rainfall could trigger flash flooding or debris
  flows, especially in and near recent wildfire burn scars.

* ADDITIONAL DETAILS...
  - https://www.weather.gov/safety/flood

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action
should Flash Flood Warnings be issued.

Local emergency services are monitoring the situation and will issue
a public statement as conditions warrant. PLAN NOW so you will know
what to do in an emergency. Keep informed by listening to local
radio and television for statements and possible warnings. Follow
the advice of public safety officials.

&&

$$

Flood Watch
National Weather Service Great Falls MT
159 AM MDT Wed Aug 27 2025

MTZ327-271600-
/O.EXT.KTFX.FF.A.0002.250827T1500Z-250828T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Northwest Beaverhead County-
Including the following locations: Jackson and Wisdom
159 AM MDT Wed Aug 27 2025

...FLASH FLOOD WATCH FOR THE BIG HOLLOW, GROUSE, SAWLOG, AND SOUTH
FORK BURN SCAR NOW IN EFFECT FROM 9 AM MDT THIS MORNING THROUGH THIS
EVENING...

* WHAT...Flash flooding and debris flows caused by excessive
  rainfall continue to be possible over the Big Hollow, Grouse,
  Sawlog, and South Fork burn scars. Rainfall amounts of 1 to 2
  inches are possible in less than one hour from thunderstorms.

* WHERE...A portion of southwest Montana, including the following
  area, Northwest Beaverhead County.

* WHEN...From 9 AM MDT this morning through this evening.

* IMPACTS...Heavy rainfall over the Big Hollow, Grouse, Sawlog, and
  South Fork burn scars is expected up to and during the period of
  the watch. Residents near the Big Hollow, Grouse, Sawlog, and
  South Fork burn scars should prepare for potential flooding
  impacts. Be sure to stay up to date with information from local
  authorities. Heavy rainfall could trigger flash flooding of
  low-lying areas, urbanized street flooding, and debris flows in
  and near recent wildfire burn scars.

* ADDITIONAL DETAILS...
  - National Weather Service Meteorologists are forecasting heavy
    rainfall over the burn scar, which may lead to flash flooding
    and debris flows.
  - http://www.weather.gov/safety/flood

PRECAUTIONARY/PREPAREDNESS ACTIONS...

PLAN NOW so you will know what to do in an emergency. Keep informed
by listening to local radio and television for statements and
possible warnings. Follow the advice of public safety officials.

&&

$$

Brusda