820
FNUS21 KWNS 181530
FWDDY1

Day 1 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
1029 AM CDT Tue Aug 18 2026

Valid 181700Z - 191200Z

Minor changes were made to the Elevated area over the Columbia
Basin. In agreement with the latest forecast guidance, portions of
the nearby Snake River over southeastern WA were added into the
Elevated area. During peak heating with temperatures near to just
above normal, afternoon RHs will fall to near 15% with sustained
westerly winds of 10-15 mph within and adjacent to the Snake River
valley through WA. Elsewhere, over the southern Plains, the forecast
remains on track as previously described. Occasionally gusty diurnal
winds may promote brief near-elevated conditions over portions of
the Snake River Plain in ID and across the lower elevations of the
southern Great Basin this afternoon as well.

..Stearns.. 08/18/2026

.PREV DISCUSSION... /ISSUED 1227 AM CDT Tue Aug 18 2026/

...Synopsis...
Heights with the western ridge will rise again today, with warming
temperatures and dry conditions across much of the Pacific
Northwest. Along the northern periphery of the ridge, a shortwave
passage will bring breezy conditions to areas east of the Cascades.
Dry and breezy conditions will also be possible south of a frontal
boundary across western Oklahoma into the Texas Panhandle.

...Portions of the Columbia Basin...
A split flow regime aloft will induce west-northwesterly flow over
Washington, and southwest-westerly flow over Oregon. Combined with
lee surface troughing, wind speeds will increase across the Cascade
Gaps. West-northwesterly surface winds of around 10-15 mph will
encompass a broad area of the Columbia Basin, with stronger winds of
20-30 mph within the gaps. At peak heating, relative humidity values
will decline to around 15-20 percent. Broadly elevated fire weather
conditions are expected in the lee of the Cascades, with locally
critical conditions possible.

...Southern Plains...
Drought conditions are prominent across much of the region,
expanding from the Texas Panhandle into western/central Oklahoma to
produce a stressed fuel environment. Breezy and dry conditions are
expected near the surface trough across the Texas Panhandle into
western Oklahoma. Profiles will be deeply mixed, with temperatures
approaching the 100s F again this afternoon. This will support
afternoon relative humidity values of 10-15% amid southwest winds of
15-20 mph, maintaining an Elevated risk area.

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

$$