Storm Prediction Center Day 1 Fire Weather Outlook
Created: Wed Oct 9 16:58:02 UTC 2019 (
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Storm Prediction Center Day 1 Fire Weather Outlook
Created: Wed Oct 9 16:58:02 UTC 2019 (
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Click for Day 1 FireWX Areal Outline Product
ZCZC SPCFWDDY1 ALL
FNUS21 KWNS 091657
Day 1 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
1157 AM CDT Wed Oct 09 2019
Valid 091700Z - 101200Z
...EXTREMELY CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE WESTERN
SACRAMENTO VALLEY INTO THE NORTHERN COAST RANGES...
...CRITICAL FIRE WEATHER AREA FOR THE SACRAMENTO VALLEY...NORTHERN
COAST RANGES AND SIERRA NEVADA FOOTHILLS...
...CRITICAL FIRE WEATHER AREA FOR SOUTHERN NEVADA...NORTHERN
ARIZONA...SOUTHERN/EASTERN UTAH AND WESTERN COLORADO...
Expanded the critical area north and eastward in western Colorado
and into far southern Wyoming where high resolution guidance
suggests critical conditions are likely and current surface
observations are already near critical criteria. In addition,
expanded the critical area southward in Arizona for the same
reasons.
The California critical/extremely critical areas appear on track
with no changes made. 16Z surface analysis shows the pressure
gradient has strengthened considerably over the past 6 hours with a
7mb gradient between Mount Shasta (KMHS) and Redding (KRDD) and this
gradient will continue to strengthen through the day. The effects of
this strengthening gradient can already be seen in Redding where
winds are already around 30 mph with relative humidity less than 25
percent. As downslope drying continues and the pressure gradient
strengthens, these winds are only expected to increase and relative
humidity is expected drop considerably and move southward down the
valley through the remainder of the morning and through the
afternoon/evening.
..Bentley.. 10/09/2019
.PREV DISCUSSION... /ISSUED 0232 AM CDT Wed Oct 09 2019/
...Synopsis...
A strong upper-level trough and associated surface cold front will
move southeast over the western CONUS today. The cold front is
expected to push into the Southwest and through much of the Rockies
and central High Plains by tomorrow morning. A strong surface high
will begin to establish in the northern Rockies with a strengthening
surface pressure gradient between the Great Basin and the California
coast resulting in strong downslope/offshore winds.
...northern/central California...
Extremely critical conditions are likely to develop at times in the
western Sacramento Valley during the afternoon into the evening with
extremely critical conditions more likely during the
evening/overnight across eastern portions of the northern Coast
Ranges. North-northeasterly sustained winds of 25-35 mph with gusts
approaching 60 mph and RH values into the single digits are likely
within the extremely critical area. Locally extremely critical
conditions may develop in portions of the higher terrain of
East/South Bay and in the Sierra Nevada Foothills including
overnight.
North-northeasterly sustained winds of 15-30 mph with gusts of 40-50
mph and RH values of 8-20% are expected within the elevated/critical
areas. Elevated/critical conditions will begin late morning and
continue into the overnight periods with the higher terrain and
portions of the Sacramento Valley favored overnight. Fuels are
driest in/around the Bay Area with ERCs/100-hour dead fuel moisture
above/below the 90th/10th percentiles. However, given the expected
winds/RH and lack of widespread precipitation this fall, fine fuels
will be receptive to ignition/spread with some heavier fuels also
receptive as supported by 100-hour dead fuel moisture values around
the 80th percentile in the Sierra Nevada Foothills.
...southern Great Basin into the Colorado Rockies...
Critical conditions will develop ahead of the surface cold front
stretching from southern Nevada into northern Arizona,
southern/eastern Utah, and western Colorado. Southwest sustained
winds of 20-25 mph and RH values of 8-15% are expected. Elevated
conditions will develop east of the High Sierra into southern
Wyoming and eastern Colorado. Locally critical conditions may
develop in southern Colorado where downslope enhancement and lee
cyclogenesis strengthen west-southwest winds. Fuels are critically
dry across much of Colorado with ERCs mostly above the 90th
percentile.
The cold front will begin to impact the delineated areas during the
afternoon and move south/southeast through the region during the
evening and overnight with strong north-northwest winds and a 15-30
degree F temperature drop behind the front. Dry/windy post-frontal
conditions in southern Nevada into the Mojave and Sonoran Deserts
will continue overnight.
...southern California...
Elevated/locally critical conditions will begin late tonight across
portions of the Transverse Ranges in southern California. Northerly
sustained winds of 15-20 mph with gusts of 25-35 mph and RH values
of 10-20% are likely tonight with critical conditions likely
beginning Thursday morning.
...Please see www.spc.noaa.gov/fire for graphic product...