U.S. Day 1 Fire Weather Outlook
ZCZC SPCFWDDY1 ALL
FNUS21 KWNS 231700
Day 1 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
1100 AM CST Thu Jan 23 2025
Valid 231700Z - 241200Z
...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF SOUTHERN CALIFORNIA...
A minor expansion was made to the Critical highlights in Los Angeles
County, based on the latest observations and high-resolution
guidance. As of 15Z, the LAX-DAG pressure gradient was at -8.6 mb
(critical conditions typically associated with -5 mb or less), and
this offshore gradient will likely remain at peak values for the
next couple hours. The latest surface observations show widespread
critical conditions across southern CA, with gusts upwards of 60-75
mph and single-digit RH over the wind-prone mountains. These
localized extremely critical conditions will persist through this
afternoon before gradually subsiding into tonight. Elsewhere across
the lower elevations, 20-30 mph sustained east-northeasterly surface
winds (with 30-40 mph gusts) and single-digit RH will also continue
through at least this afternoon, resulting in high-end critical
conditions.
..Weinman.. 01/23/2025
.PREV DISCUSSION... /ISSUED 0143 AM CST Thu Jan 23 2025/
...Synopsis...
A mid-level trough will eject into the southern Plains today, with a
strong surface pressure gradient persisting over southern California
for the first half of the period before gradually relaxing. From the
start of the period into at least mid-afternoon, strong and dry
offshore flow will continue to support dangerous, rapid
wildfire-spread potential. Sustained wind speeds well exceeding 20
mph amid 10 percent RH should be common around the Los Angeles
metropolitan area southeast to the Laguna Mountain range. However,
terrain-favoring areas (especially at higher elevations) may see
winds sustain over 50 mph for at least brief periods of time,
perhaps with gusts reaching 70 mph, as RH drops to single-digits.
Given very dry fuels, at least localized and brief Extremely
Critical conditions should be expected, with high-end Critical
conditions more likely on a widespread basis.
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U.S. Day 2 Fire Weather Outlook
ZCZC SPCFWDDY2 ALL
FNUS22 KWNS 232000
Day 2 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0200 PM CST Thu Jan 23 2025
Valid 241200Z - 251200Z
An Elevated area was added over portions of western North TX into
southwest OK. Here, guidance is in good agreement, depicting 15-25
mph sustained southwesterly surface winds (with higher gusts) amid
15-20 percent RH. While fuels are somewhat marginal across much of
the area, the latest fuels report suggests that they are at least
modestly supportive of a large fire -- warranting the highlights.
Dry/breezy conditions are also expected farther northwest into the
TX Panhandle, though fuels appear less receptive here. For
additional details, see the previous discussion below.
..Weinman.. 01/23/2025
.PREV DISCUSSION... /ISSUED 0144 AM CST Thu Jan 23 2025/
...Synopsis...
A surface pressure gradient should be diffusing across southern
California as a mid-level trough amplifies along the West Coast,
encouraging surface low development with onshore flow by late
tomorrow (Friday) afternoon. Since some dry offshore flow may be
ongoing at the start of the period (12Z Friday) though, Elevated
highlights were introduced given lingering very dry air (10-15
percent RH) and highly receptive fuels.
Meanwhile, the deepening of the West Coast upper trough will also
support strong surface lee troughing and associated downslope flow
across the southern High Plains Friday afternoon. Guidance consensus
shows RH dipping into the 10-20 percent range by afternoon peak
heating, with sustained southwesterly surface winds exceeding 20 mph
on a widespread basis. While such conditions would typically
necessitate fire weather highlights, fuel receptiveness currently
appears too marginal to support widespread, significant
wildfire-spread potential.
U.S. Day 3-8 Fire Weather Outlook
ZCZC SPCFWDD38 ALL
FNUS28 KWNS 232150
Day 3-8 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0350 PM CST Thu Jan 23 2025
Valid 251200Z - 311200Z
On Day 3/Saturday, west-southwesterly deep-layer flow will gradually
strengthen across the Southwest, southern Great Basin, and inland
southern CA ahead of a midlevel trough. As a result, dry/breezy
conditions will develop across the region, with locally elevated
fire-weather conditions possible -- especially across portions of
southern/central AZ and the inland mountains of southern CA. By Day
3/Saturday evening/night, precipitation will likely overspread much
of southern CA and persist through the weekend. This should reduce
fire-weather concerns through the remainder of the extended forecast
period.
From Day 4/Sunday through Day 6/Tuesday, locally dry/breezy
conditions will be possible across the Southwest into the southern
Rockies each afternoon, as the midlevel trough/low (and strong flow
aloft) continues slowly east-southeastward. Similar conditions will
be possible across the southern High Plains on Days
7-8/Wednesday-Thursday. This may favor periods of elevated
fire-weather conditions, though mostly marginal fuels should limit
the potential for critical conditions.
..Weinman.. 01/23/2025
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