Storm Prediction Center Day 2 Fire Weather Outlook
Created: Sat Nov 10 08:02:03 UTC 2018 (
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Storm Prediction Center Day 2 Fire Weather Outlook
Created: Sat Nov 10 08:02:03 UTC 2018 (
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Click for Day 2 FireWX Areal Outline Product (KWNSPFWFD2)
ZCZC SPCFWDDY2 ALL
FNUS22 KWNS 100801
Day 2 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0201 AM CST Sat Nov 10 2018
Valid 111200Z - 121200Z
...EXTREMELY CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE
CALIFORNIA FOOTHILLS...
...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF SOUTHERN CALIFORNIA...
...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF NORTHERN CALIFORNIA...
...Synopsis...
A positively tilted longwave trough, already established across the
western CONUS, will continue to deepen throughout the Day 2 period,
reinforcing 1040+ mb surface high pressure across the Great Basin.
Day 2 will begin with a strong pressure gradient and resultant
offshore flow across portions of northern and southern California,
followed by a brief period of weakening of the fortified pressure
gradient during the early afternoon hours, before re-intensification
late in the Day 2 (Sunday night/early Monday morning) period
coincident with a secondary surge of a surface high. As such,
strong/dry offshore flow will continue across California, promoting
surface wind/RH conditions favorable for large fire growth in
terrain favoring areas for extended periods of time.
...Southern California...
A critically strong pressure gradient will be established across
southern California at the start of Day 2. Within the 1200-1800 UTC
time frame, 20+ mph downslope/offshore winds are expected to be
widespread across much of the California Foothills, where critically
low RH and critically dry fuels will be abundant, hence
elevated/critical delineations have been made. In addition, very
strong channeled flow in terrain-favoring areas (predominantly
around the San Gabriel and Santa Monica Mountains) will result in
sustained north-northwesterly wind speeds of 30+ mph, with the
possibility of gusts reaching as high as 45-60 mph. These wind
speeds, combined with the expected critically low RH (down to single
digits)/dry fuels, will support a volatile environment for the rapid
growth/spread of both new and ongoing wildfires, hence the
introduction of an extremely critical delineation. While a brief
respite from the strongest winds may occur during the afternoon
hours, re-invigoration of the pressure gradient and resultant
offshore flow is expected early Monday morning, where critical
wind/RH conditions are expected to resume.
...Northern California...
With relatively strong high pressure traversing the area to the
west, a strong pressure gradient will persist into the late morning
hours across northern California. With surface RH remaining
critically low, and with fuels remaining dry across the area, 20-25
mph northerly winds induced by the aforementioned pressure gradient
will promote elevated to critical surface conditions across the
northern Sacramento Valley throughout the morning.
..Squitieri.. 11/10/2018
...Please see www.spc.noaa.gov/fire for graphic product...