Riverside, CA...San Bernardino, CA...Fontana, CA...Santa Clarita, CA...Moreno Valley, CA...
ZCZC SPCFWDDY1 ALL
FNUS21 KWNS 161645
Day 1 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
1045 AM CST Sat Jan 16 2021
Valid 161700Z - 171200Z
...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF SOUTHERN CALIFORNIA...
The previous forecast remains on track. The latest high-resolution
model guidance suggests that a brief uptick in offshore flow may be
observed late this morning into early afternoon across portions of
the southern Transverse Ranges in southern California. Thereafter,
offshore winds should begin to gradually subside with the onset of
upper ridging. Guidance consensus also continues to show locally
Elevated/Critical conditions possible by afternoon peak heating
along the immediate lee of the Sacramento to Davis mountains across
southern New Mexico into southwestern Texas. No fire weather
highlights have been added given the continued mediocre
receptiveness of fuels and the spatially confined nature of the
favorable surface winds/RH overlap. Lastly, dry and occasionally
breezy conditions are still likely along the Georgia/Florida border
later this afternoon, but Elevated conditions should remain sparse
enough to warrant the withholding of Elevated highlights, especially
given recent rainfall accumulations.
.PREV DISCUSSION... /ISSUED 1200 AM CST Sat Jan 16 2021/
An upper-level low in place across the Midwest will gradually weaken
and lift to the northeast into New England through today. As this
occurs, cool dry air will continue to overspread the eastern
two-thirds of the CONUS. Pressure gradient winds will be weaker
compared to previous days, which will limit the fire weather
potential despite the dry air. To the west, a slight
re-intensification of surface high pressure across the
inter-mountain West will maintain offshore winds and support another
day of fire weather concerns.
Early morning surface observations from coastal southern CA show RH
values struggling to recover out of the teens with wind gusts into
the 20-40 mph range. Elevated to localized critical conditions are
already ongoing and are expected to increase in coverage through the
day. RH values should remain in the teens, and fuels remain
receptive due to no recent precipitation. Upper-level height rises
along the West Coast will help augment the surface high to the north
of the region, resulting in a strengthening offshore pressure
gradient and increasing winds (a -5 to -7 mb LAX-DAG gradient
appears likely by mid-day). Weak upper-level support will limit the
overall wind potential, but gusts up to 40-45 mph are likely. While
critical conditions appear most likely for portions of Ventura, Los
Angeles, and southwest San Bernardino counties, transient/localized
critical conditions may extend southward to the U.S./Mexico border.
Winds should begin abate somewhat by the late afternoon hours, but
guidance continues to suggest that breezy conditions could persist
into early Sunday morning for some locations. However, falling
temperatures and gradually increasing RH may limit the fire weather
threat for early Sunday.
...Central New Mexico into southwest Texas...
The re-intensification of the western surface High will support
15-25 mph westerly downslope winds along the higher terrain of
central NM into southwest TX. Overnight RH values in the teens to
30% range are expected to remain in the teens or fall to the low 20s
by this afternoon, which should support at least elevated wind/RH
conditions. However, fuels across this region remain somewhat
marginal and should limit the overall fire weather concern.
...Northern Florida and southern Georgia...
Dry air advecting into the region today will help RH values fall to
near 30% for many locations along the FL/GA border. Breezy winds at
around 15 mph are also anticipated and could support elevated
wind/RH criteria for some areas. Despite dry conditions in the
previous few days, recent radar estimates show 0.1-0.25 inches of
rain have fallen over the past 24 hours, which should limit fuel
...Please see www.spc.noaa.gov/fire for graphic product...
CLICK FOR DAY 1 FIREWX AREAL OUTLINE PRODUCT (KWNSPFWFD1)