Day 1 Fire Weather Outlook  
NWS Storm Prediction Center Norman OK
1200 PM CDT Thu Jul 03 2025

Valid 031700Z - 041200Z

...Central California...
An approaching mid-level short wave trough will promote enhanced dry
downslope winds along and leeward of the Diablo Range into the San
Joaquin Valley this afternoon. West-northwest winds of 10-15 mph
with locally sustained 20 mph combined with relative humidity as low
as 10% will support a few hours of elevated fire weather conditions
amid dry fuels.

...Northern Great Basin and Upper-Colorado River Basin...
Isolated dry thunderstorm threat was expanded into south-central OR
and north-central NV with latest model guidance and observed
soundings indicating precipitable water values holding in the
0.50-0.80 inch range for this afternoon. The advancing short-wave
trough will support faster storm motions particularly across
southeastern OR. In addition, falling 500 DM heights and mid-level
jet support will keep a nocturnal thunderstorm threat for
southeastern OR and southern Idaho through 12Z Friday. Otherwise, a
mix of wet/dry thunderstorms across the Upper CO River Basin and
central Mountains of UT could support new ignitions in pockets of
existing dry fuels.

..Williams.. 07/03/2025

.PREV DISCUSSION... /ISSUED 0211 AM CDT Thu Jul 03 2025/

...Synopsis...
A compact shortwave trough moving across northern CA will accompany
40-50 kt westerly flow across the northern Great Basin. This will
encourage dry downslope flow across parts of western NV and the
northern Great Basin. At the same time, continued monsoon moisture
will allow scattered showers and thunderstorms over the
Intermountain West with isolated lightning.

...Northern Great Basin...
Dry and breezy conditions are expected today and tonight in the lee
of the Sierra and northern Great Basin ahead of the shortwave
trough. Sustained 15-20 mph surface winds are expected from the
west/southwest through the day. A dry and deep boundary layer will
also support RH below 15-20%. Despite some recent rainfall, area
fuels remain receptive across much of NV and the northern Great
Basin. Widespread elevated and locally critical fire-weather
conditions are likely.

...Dry Thunder...
As the upper trough moves into the West, monsoon moisture will be
shunted eastward compared to the last several days. Still, PWATS
around 0.6-0.8 inches across western CO and into the northern
Rockies will be sufficient to support scattered showers and
thunderstorms this afternoon and evening. Fuel receptiveness has
decreased with multiple rounds of showers and storms this week.
Still, drier pockets remain and lightning outside of the heavier
precipitation cores will be capable of ignitions. This appears most
likely over parts of northern CO to eastern ID, where less rainfall
has been observed. Will maintain IsoDryT highlights for occasional
lighting strikes within receptive fuels.

...Please see www.spc.noaa.gov/fire for graphic product...