Red Flag Warning 21, NWS Boise, ID

008 
WWUS85 KBOI 111450
RFWBOI

URGENT - FIRE WEATHER MESSAGE
National Weather Service Boise ID
850 AM MDT Wed Sep 11 2024

...SCATTERED STRONG THUNDERSTORMS TODAY INTO THE EVENING...
...BREEZY WINDS OUTSIDE OF STORMS IN SOUTHERN ZONES...

.A strong upper level low will create conditions very favorable
for the development of thunderstorms through this evening. Storms
have formed in eastern OR early this morning and will move into 
SW ID around noon MDT. After this first round moves through, 
additional storms should form and then continue to move northeast 
throughout the region. Scattered lightning is likely. Strong to 
severe outflow gusts are possible near storms. Heavy rain rates on
burn scars pose a localized flash flood and debris flow risk. 
Storms weaken to showers Wednesday night and chances of wetting 
rains increases through Thursday.

IDZ400>403-420-421-423-424-426-ORZ636-637-646-120300-
/O.CON.KBOI.FW.W.0021.240911T1800Z-240912T0300Z/
Northern Boise BLM-Western Payette National Forest-
Eastern Payette National Forest-Northern Boise National Forest-
Treasure Valley BLM-
Southern Boise National Forest/Western Sawtooth National Forest-
Owyhee Mountains-Western Twin Falls BLM-Southern Highlands-
Burns BLM-Vale BLM-Baker Valley-
850 AM MDT Wed Sep 11 2024 /750 AM PDT Wed Sep 11 2024/

...RED FLAG WARNING REMAINS IN EFFECT FROM NOON MDT /11 AM PDT/
TODAY TO 9 PM MDT /8 PM PDT/ THIS EVENING FOR LIGHTNING FOR FIRE
WEATHER ZONES 400, 401, 402, 403, 420, 421, 423, 424, AND 426...

* Thunderstorms...Scattered to isolated.

* Outflow Winds...50 to 60 mph.

* Timing...From noon MDT /11 AM PDT/ today to 9 PM MDT /8 PM 
  PDT/ this evening.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Red Flag Warning means that critical fire weather conditions
are either occurring now, or will occur shortly.

&&

$$


L

353 
WWUS85 KBOI 120236
RFWBOI

URGENT - FIRE WEATHER MESSAGE
National Weather Service Boise ID
836 PM MDT Wed Sep 11 2024


IDZ400>403-420-421-423-424-426-ORZ636-637-646-120345-
/O.EXP.KBOI.FW.W.0021.000000T0000Z-240912T0300Z/
Northern Boise BLM-Western Payette National Forest-
Eastern Payette National Forest-Northern Boise National Forest-
Treasure Valley BLM-
Southern Boise National Forest/Western Sawtooth National Forest-
Owyhee Mountains-Western Twin Falls BLM-Southern Highlands-
Burns BLM-Vale BLM-Baker Valley-
836 PM MDT Wed Sep 11 2024 /736 PM PDT Wed Sep 11 2024/

...RED FLAG WARNING WILL EXPIRE AT 9 PM MDT /8 PM PDT/ THIS
EVENING FOR LIGHTNING FOR FIRE WEATHER ZONES 400, 401, 402, 403,
420, 421, 423, 424, 426, 636, 637, AND 646...

Only a few thunderstorms remain across the area so the warning was
allowed to expire. 

$$


L

Area Forecast Discussion
National Weather Service Boise ID
1015 AM MDT Tue Sep 10 2024

.DISCUSSION...A trough over the Gulf of Alaska is moving
southeastward toward the Pacific NW today. Expect increasing
clouds later this afternoon with isolated showers and
thunderstorms northwest of Baker and Burns OR this afternoon and
evening. One last warm day with temperatures around 10 degrees
above normal today before temperatures fall 10-20 degrees on
Wednesday. The cold front will move through the area on
Wednesday morning in eastern OR and Wednesday afternoon in
southwest Idaho, with showers and thunderstorms along the cold
front. Thunderstorms will be capable of wind gusts up to 60 mph
and hail up to 1" on Wednesday afternoon. The Storm Prediction
Center has much of SE Oregon and southwest Idaho in a marginal
risk for severe weather on Wednesday for these threats as well.
Flash flooding and debris flows remains a concern from heavy
rainfall rates over recent burn scars. Current forecast on track
with no updates.

&&

.AVIATION...Increasing high clouds. Isolated showers and
thunderstorms W of KBKE KBNO late this afternoon. Low VFR with
areas of IFR conditions and mountain obscuration from wildfire
smoke. Surface winds: NW- SW 5-15 kt. Gusts up to 25 kt along
the NV border and in central ID. Winds aloft at 10kft MSL:
W-SW 15-25 kt.

KBOI...Low VFR in smoke. Surface winds: SE 5-10 kt shifting to the
northwest by Tue/22Z.

&&

.PREV DISCUSSION...
SHORT TERM...Today through Thursday night...One more day of
warm and dry conditions today before a major pattern change
takes place. Temperatures today will be around 10 degrees above
normal with valley highs in the lower 90s. It will be breezy in
the higher elevations with lighter winds in the valleys. Smoky
conditions will continue from wildfires in the central Oregon
and central Idaho mountains. Clouds will increase ahead of an
upper low approaching the Pacific Northwest coast. This feature
will bring a 20-40% chance of showers and slight chance of
thunderstorms to northeast Oregon and west- central Idaho
tonight.

The center of the low will begin to move inland on Wednesday and
push a cold front through our area. The front will reach
southeast Oregon by late morning and move across southwest Idaho
in the afternoon. Showers and scattered thunderstorms will
develop along and behind the front. Instability and wind shear
will increase ahead of the low center, allowing for strong
thunderstorms to develop Wednesday afternoon and evening with
gusty winds 40-60 mph, small hail, and heavy rain possible. PWs
will only reach around the 60th-70th percentile which will limit
overall flash flooding threat, but flash flooding and debris
flows will be a concern from heavy rainfall over recent burn
scars. Temperatures will cool around 15 degrees from today.
Winds outside of thunderstorms will become gusty behind the cold
front.

The low will gradually move east Wednesday night and Thursday
with showers and a slight chance of thunderstorms continuing
near the low center. This will result in the highest chance of
rain over the central Idaho mountains (60-90% chance) and lesser
chances (30-50%) elsewhere. Areas of heavier rainfall are
possible as moisture wraps around the backside of the low. Storm
total rainfall will vary significantly across the area with the
highest totals expected in the central Idaho mountains where
several large wildfires continue to burn. Currently there is a
50-80% chance of at least 0.5 inch of precipitation and a 10-30%
chance of at least 1 inch in the central Idaho mountains.
Elsewhere, 0.10 to 0.25 inch of precipitation is most likely,
but localized heavier totals are possible. Snow levels will
fall to 8000-9000 feet on Thursday, allowing the highest peaks
to see light snow accumulations. Temperatures will cool another
10 degrees from Wednesday, with highs 10-15 degrees below
normal. Gusty northwest winds will continue as the low moves
east. Precipitation chances will decrease Thursday night as the
low lifts into Montana.

LONG TERM...Friday through Tuesday...Dry conditions along with a
warming trend are favored in the latest models that commences on
Friday and continues into the weekend. Temperatures on Friday
average about 5 degrees below normal in the wake of the exiting
upper trough. Temperatures then warm to slightly above normal over
the weekend ahead of the next Pacific trough as it approaches the
coast. Models diverge with regard to timing and strength of the
trough early next week. Most ensemble members indicate the trough
reaching our area by Tuesday with an uptick in shower chances from
15-30 percent on Monday to 30-50 percent on Tuesday. Temperatures
trend cooler each day with highs on Tuesday around 5 to 10 degrees
below normal.

&&

.BOI WATCHES/WARNINGS/ADVISORIES...
ID...Fire Weather Watch from Wednesday afternoon through Wednesday
     evening IDZ400>403-420-421-423-424-426.
OR...Fire Weather Watch from Wednesday morning through Wednesday
     evening ORZ636-637-646.

&&

www.weather.gov/Boise

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DISCUSSION...KA
AVIATION.....KA
SHORT TERM...ST
LONG TERM....BW