ZCZC SPCFWDDY1 ALL
   FNUS21 KWNS 261635

   Day 1 Fire Weather Outlook  
   NWS Storm Prediction Center Norman OK
   1135 AM CDT Wed Aug 26 2026

   Valid 261700Z - 271200Z

   ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF NORTHEASTERN
   CALIFORNIA...NORTHWESTERN NEVADA...AND SOUTHEASTERN OREGON...

   As an upper trough impinges upon the Pacific Northwest this
   afternoon, strong southwesterly flow aloft will support an expansive
   fire weather threat across the northern Intermountain West. A
   tightening surface pressure gradient along the Cascades and emerging
   surface low will compel sustained southwest winds of 10-15 mph
   (gusts of 20-30 mph in terrain-favored areas) and RH values of
   15-20% in the Columbia Basin and northern Sierra Nevada. A region of
   critical conditions are likely across northeastern California,
   northwestern NV, and southeastern Oregon where RH values will
   decline to less than 15% and sustained southwest winds increase to
   20 mph. Notably, in the last 48 hours, numerous lightning strikes
   occurred with minimally observed precipitation (less than 0.15")
   within today's Critical risk area and southern extent of the
   Elevated highlights, increasing concerns for holdovers to emerge.
   Fuels remain receptive across much of the region, with active fires
   in the landscape and observed ERCs ranging from the 90-95th
   percentile.

   12z REFS/HREF continue to depict 50-60% probabilities of
   thunderstorms across the Northern Rockies this afternoon. Forecast
   soundings portray deep inverted-V profiles, MUCAPE vales up to 1200
   J/kg, and LCL-EL winds of 25-35 kt; as a result, accumulating
   precipitation at the surface is expected to be minimal, escalating
   the potential for lightning-induced ignitions within an increasingly
   receptive fuelscape. Isolated Dry Thunderstorm highlights were
   trimmed out of far northeastern Washington where afternoon
   thunderstorms have become less probable.

   Farther south, offshore winds will redevelop this evening in
   portions of southern California. Elevated fire weather conditions
   are expected in favored terrain gaps and downslope areas of
   LA/Ventura/Santa Barbara counties. Please see the previous
   discussion for more details.

   ..Elizalde-Garcia.. 08/26/2026

   .PREV DISCUSSION... /ISSUED 0107 AM CDT Wed Aug 26 2026/

   ...Synopsis...
   An upper-level trough edging into the Pacific Northwest will bring
   widespread fire weather concerns to much of the interior of the
   Northwest, northern Great Basin and northern Rockies today. Isolated
   dry thunderstorms are expected across much of the northern Rockies,
   while dry and breezy conditions develop farther west across the
   Columbia Basin south towards the northern Great Basin and
   northeastern CA. An increasing offshore pressure gradient will bring
   an elevated fire weather threat to parts of southern CA late this
   afternoon into the overnight hours as dry and breezy conditions
   develop.

   ...Northeastern California into northwestern Great Basin...
   A narrow corridor of critical fire weather conditions is likely
   today across the northwestern fringe of the Great Basin. The
   upper-level trough and attendant increasing deep layer southwest
   flow will support southwest surface winds of around 20 mph. An
   existing dry air mass with RH falling to as low as 10% and receptive
   fuels will promote wildfire spread, where several active fires are
   present.

   ...Columbia Basin southward towards the northern Great Basin and
   northern Sierra Nevada...
   An upper trough encroaching upon the Pacific Northwest will
   strengthen mid-level southwest winds across much of the northwestern
   U.S. today. Although upper-level cloud cover will inhibit full
   mixing potential across the region, the deep-layer southwest flow
   aided by an emerging surface low across eastern WA/OR will
   contribute to southwest winds of 10-15 mph from northeastern CA into
   eastern OR and the Columbia Basin. Relative humidity reductions by
   peak afternoon heating will likely reach around 15%.

   ...Northern Rockies into northern Washington...
   The approaching upper trough will promote broad but diffuse forcing
   for ascent as a mid/upper moisture plume pushes into the northern
   Rockies. Afternoon instability (MLCAPE values in the 500-1000 J/kg
   range), a dry sub-cloud layer and northeast shower/thunderstorm
   trajectories of 25-35 mph with PWATs generally less than 0.8",
   should limit surface rainfall this afternoon and evening as isolated
   dry thunderstorms develop across the central ID mountains northward
   into the ID Panhandle and western MT.

   ...Southern California...
   High pressure aloft will continue to support dry conditions and near
   record high temperatures in the 90s and 100s farther inland away
   from coastal influence. Fuels continue to dry, becoming increasingly
   receptive each day. An offshore pressure gradient will promote
   primarily north winds of 15-25 mph amid RH of 15-20% this evening
   into early D2/Thursday morning. Winds will be strongest in favored
   terrain gaps and downslope areas in LA/Ventura/Santa Barbara
   counties.

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

   CLICK FOR DAY 1 FIREWX AREAL OUTLINE PRODUCT (KWNSPFWFD1)