523
FNUS22 KWNS 211845
FWDDY2

Day 2 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0144 PM CDT Thu Aug 21 2025

Valid 221200Z - 231200Z

The IsoDryT areas were merged and expanded. Scattered mixed wet/dry
thunderstorms are likely across much of Utah and western Colorado,
with PWAT values of 0.7-0.9" and storm motions of 10-20 knots.
Wetting rain is likely in some areas due to the increasing monsoonal
moisture and training of storms. However, due to the very/record dry
fuels, potential for deep pyroconvection on active large fires, and
anticipated locally elevated conditions, the IsoDryT was expanded.
Isolated mixed wet/dry thunderstorms are possible in portions of the
Peninsular Ranges of southern California and into the Mojave, and
isolated high-based showers with embedded thunderstorms are also
possible in southern California overnight.

An Elevated area was introduced for portions of eastern New England.
Dry/breezy northerly winds are likely as Hurricane Erin passes
offshore and fuels are receptive, especially in Maine, where fire
activity has increased recently.

Hot/dry/unstable/breezy conditions are expected along the thermal
trough extending from southern California into the Northwest. Higher
probabilities of the Hot, Dry, Windy Index exceeding the 95th
percentile and locally elevated winds/RH are forecast in portions of
California, Oregon, and Washington near the thermal trough.

..Nauslar.. 08/21/2025

.PREV DISCUSSION... /ISSUED 0157 AM CDT Thu Aug 21 2025/

...Synopsis...
As the upper ridge persist over the West, several subtropical
perturbations will arrive from the south, ushering in another surge
of monsoon moisture. Isolated thunderstorms are likely across the
southern Sierra and into parts of the Great Basin Friday. With very
warm surface temperatures and dry sub-cloud layers, little wetting
rainfall is expected. This should allow for isolated dry lightning
atop receptive fuel mainly over portions of California and Nevada
where fuels are most receptive. Some localized dry and breezy winds
may also occur outside of the thunderstorms over the central great
Basin Friday.

Over the southern Great Basin and Southwest, higher PWATs near 1
inch are expected. Isolated to widely scattered thunderstorms are
likely through the afternoon. However, a wetter storm mode is more
probable across northern Arizona, southern Utah and western
Colorado, where fuels are also less receptive.

...California...
Isolated thunderstorms are likely in portions of southern California
mountains and over the Mojave. A wetter mode is expected with max
PWATs near 1.2 to 1.3 inches and little in the way of steering flow.
However, cloud bases are likely to be over 3-km with a hot/dry
sub-cloud layer limiting some precipitation efficiency. Sporadic dry
strikes re possible given the degree of extreme heat and dry fuels
but coverage is not expected to reach 10% or greater. Additionally,
very hot, dry and unstable conditions may support plume dominated
fire behavior with existing large fires.

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

$$