FNUS28 KWNS 132150
FWDD38

Day 3-8 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0348 PM CST Wed Nov 13 2019

Valid 151200Z - 211200Z

A low-amplitude ridge will reside across the Continental Divide at
the beginning of the extended period. Quasi-zonal flow aloft will
exist relatively briefly before flow becomes more amplified again by
D5/Sunday. At that time, upper-level ridging will intensify across
the West Coast. Late in the period, model solutions diverge with
regard to the evolution of an upper-level trough impacting portions
of the West. Depending on the evolution of that feature, southern
California may end up seeing meaningful precipitation and
diminishing fire weather concerns. Key surface features this period
will be a surface high within the Pacific Northwest that will move
southeastward into Great Basin from D4/Saturday into D5/Sunday. Cool
temperatures and recent/expected precipitation will keep fire
weather concerns across much of the eastern two-thirds of the CONUS
low.

...D4/Saturday and D5/Sunday...California...
Medium-range deterministic/ensemble guidance continue to show
confidence in surface high pressure moving into the Pacific
Northwest behind a cold front on Saturday. As this surface high
progresses southeast, downsloping into the northern Sacramento
Valley and along the western Sierra slopes remains possible.
Upper-level support is expected to be relatively modest, though
there still remains some uncertainty as to how progressive the
northerly mid-level jet will be in the ECMWF ensemble. A relatively
broad 40% will be maintained due to continued uncertainty, though
trends suggest potentially critical conditions are not likely to be
expansive. Fuels in the highlighted area continue to be very dry
(ERCs at record levels) and will support fire spread.

In southern California, the forecast for a weak to potentially
moderate Santa Ana winds continues on track. Trends in the offshore
pressure gradient have remained steady over the past few model runs.
Winds are expected to pick up on Saturday evening into early Sunday
morning. Upper-level winds will be most favorable during the early
portions of the event, though the offshore gradient is expected to
be maximized mid/late Sunday morning into the early afternoon. As
with northern California, ERCs across the highlighted regions are
near or above record values.

...Southern/central High Plains...
Lee troughing and an approaching weak cold front are expected to
impact the region on D4/Friday and D5/Saturday, causing surface
winds to increase. The main question continues to how low RH will
fall during the afternoon with a preponderance of guidance showing
RH near or above 30%. With this continued uncertainty, no
probabilities will be introduced.

..Wendt.. 11/13/2019

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

$$