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FNUS28 KWNS 242046

Day 3-8 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0345 PM CDT Sun Sep 24 2017

Valid 261200Z - 021200Z

Portions of CA will continue to be the main fire weather concern
during the Day 3-8/Tue-Sun period. An upper trough centered over the
Great Basin will cut-off by late Tue/early Wed over the southwestern
deserts. This will result in an increase in deep-layer
north/northeasterly winds across much of central into southern CA.
At the surface, high pressure will persist from the Pacific
Northwest and Great Basin into the Rockies. This will lead to a
favorable, albeit modest, surface pressure gradient for low level
offshore winds across CA.

...Day 3/Tue - Portions of the Sacramento Valley and Adjacent
Coastal Ranges of Northern California...

Conditions will be similar to those seen in the Day 1-2 period.
Strong boundary layer heating will result in deep mixing and
northeasterly surface winds of 15-20 mph with higher gusts in
favored mountain and foothill locations are expected. RH values will
fall into the 10-20 percent range as temperatures warm into the 80s
and low 90s.

...Days 3-8/Tue-Sun -- Portions of California...

Drying conditions will continue on Tue/Wed with RH values in the
10-15 percent range common and high temperatures in the 80s and low
90s.  Poor overnight RH recovery will further exacerbate drying of
fuels across the region. Surface winds will become gusty in wind
prone areas in the coastal ranges and foothills with sustained
speeds 15-20 mph gusting as high as 40 mph for a few hours on
Tuesday. On Wednesday, some weakening of winds is possible, but very
dry and warm conditions will remain. Some locally critical
conditions will be possible, especially on Tuesday, but the lack of
a stronger surface pressure gradient will preclude any upgrades in
probabilities at this time.

Low RH and warm temperatures with light offshore winds will continue
through the remainder of the Day 3-8 period. Offshore winds appear
to be rather light however with a weak pressure gradient and weak
flow aloft as well. Medium range guidance does indicate some
potential for winds to pick up again toward the end of the period,
but confidence is low at this time.

..Leitman.. 09/24/2017

...Please see for graphic product...

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