179
FNUS21 KWNS 061630
FWDDY1

Day 1 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
1129 AM CDT Sat Sep 06 2025

Valid 061700Z - 071200Z

The only change to the ongoing forecast was to expand the isolated
dry thunderstorm area into northern California. Here, precipitable
water values are running between 0.5"-0.75". Low-to-mid-level flow
is sufficiently strong (on the order of 20-25 knots) that, when
coupled with the low precipitable water values, any thunderstorm
that can develop would pose at least some potential for being on the
dry side.

..Marsh.. 09/06/2025

.PREV DISCUSSION... /ISSUED 0142 AM CDT Sat Sep 06 2025/

...Synopsis...
A mid-level trough will progress across the Northeast while upper
ridging persists over the Rockies, and another upper trough impinges
on the West Coast today. The West Coast upper trough will provide
enough upper support atop a dry boundary layer to encourage locally
dry and windy conditions to the lee of the northern Sierra this
afternoon. While occasional bouts of 15 mph sustained southwesterly
surface winds may overlap with 15-20 percent RH, the brief and
localized nature of these conditions preclude Elevated highlights.

Farther to the northeast, upper support from the aforementioned
upper trough will encounter greater buoyancy, which will support
scattered thunderstorm development during the afternoon into the
evening hours. Storms will be most likely over portions of the
Pacific Northwest into the northern Rockies. Here, forecast
soundings show a dry boundary layer extending to at least 700 mb,
suggesting that a mix of wet and dry thunderstorms may occur.
Regardless of precipitation production, some of these storms may
overspread patches of very dry fuels that may be easily ignited by
lightning, warranting the continuance of dry thunderstorm highlights
over the Pacific Northwest to northern Rockies.

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

$$