SPC Day 3-8 Fire Weather Outlook

[NorthGeorgiaWX]

SPC Day 3-8 Fire Weather Outlook

Day 3-8 Fire Weather Outlook  
NWS Storm Prediction Center Norman OK
0456 PM CDT Wed Jul 31 2024

Valid 021200Z - 081200Z

Broad mid-level troughing off the U.S. West Coast and associated
southwesterly flow is expected to phase with a subtle shortwave
trough moving northward along the periphery of a ridge centered over
the Western U.S. As the offshore trough moves eastward and the
shortwave becomes absorbed into the broader flow, an extended period
of isolated dry thunderstorms is expected beginning D3/Friday and
persisting through at least D6/Monday.

...D3/Friday...
Two regions for isolated dry thunderstorm occurrence have come into
focus: One over the Sierra Nevada, and one over central/eastern
Oregon and Washington. The Sierra Nevada may experience a mix of
wet/dry thunderstorms given higher forecast PWAT values. However,
storm motions of 30 kts and modest to extremely receptive fuels will
limit wetting rainfall and could result in efficient lightning-based
ignitions. In the Pacific Northwest, there is still some uncertainty
in the overall coverage of dry thunderstorms, with a potential
minima in coverage along the OR/WA border. The greatest chances for
dry lightning appears to be in Central Oregon and portions of
Northern Washington, where forecast profiles for buoyancy are
maximized over dry, deeply mixed boundary layers, and fuels are
receptive. 

...D4/Saturday through D6/Monday...
The greatest chances for dry lightning occurrence are on D4/Saturday
across the Sierra Nevada into the Northwest, and persisting across
the Northwest into Montana on Sunday. While some uncertainty remains
on the timing of upper-level forcing, as well as the extent of cloud
cover across the area, dry thunderstorms over receptive fuels appear
likely. On D5/Sunday, storm motions are forecast to be at or above
30 kts, which may limit any additional wetting rainfall. The
moisture and flow associated with this system will persist D6/Monday
across far eastern portions of WA/OR into western MT. There is some
indication of dry/windy conditions across the Snake River Plain on
D5/Sunday, and portions of N CA into S OR on D6/Monday, but
uncertainty in the magnitude of surface winds precludes highlights
at this time. 

...D7/Tuesday and D8/Wednesday...
Some chances for dry thunderstorms could linger across portions of
the Northwest into the Northern Rockies on D7/Tuesday. There is also
some indication of dry/windy conditions returning to the Northwest.
However, the uncertainties in the forecast guidance preclude the
introduction of any highlight areas at this time, though will
continue to be monitored in further updates.

..Halbert/Squitieri.. 07/31/2024

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

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