Fire Weather

SPC Day 1 Fire Weather Outlook

SPC Day 1 Fire Weather Outlook
          
Day 1 Fire Weather Outlook Image
Day 1 Fire Weather Outlook  
NWS Storm Prediction Center Norman OK
1200 PM CDT Sun Sep 22 2019

Valid 221700Z - 231200Z

...NO CRITICAL AREAS...

Current water vapor satellite imagery shows a potent mid-level
trough beginning to dig into northern California. Dry air aloft is
quite evident with this feature and is forecast to impact portions
of the Northern Coastal Ranges during the overnight. Forecast
soundings capture this dry air aloft well, though relatively
efficient boundary-layer cooling in these soundings keeps this air
from mixing to the surface. However, some concern exists that strong
surface flow in localized areas will promote greater overnight
mixing than models suggest. High-resolution guidance continues to
the suggest that this will only occur on a spatially-limited basis
so no highlights will be introduced.

..Wendt.. 09/22/2019

.PREV DISCUSSION... /ISSUED 0126 AM CDT Sun Sep 22 2019/

...Synopsis...
An area of mid-level ridging is forecast to move from portions of
the Great Basin toward the central/northern Plains through tonight.
Meanwhile, a large upstream mid/upper-level trough -- and associated
area of enhanced mid-level flow -- is forecast to come onshore
across portions of northern California, Oregon, and Washington late
this afternoon and into the overnight. 

...Nevada...
A few hours of locally elevated fire weather conditions are possible
this afternoon across portions of central/southwest Nevada, where
sustained surface winds of 10-15 mph occur in conjunction with
surface RH values near 15% and receptive fuels. However, the
brief/spotty nature of these conditions precludes the introduction
of a fire weather area. 

...Northern California...
Locally elevated fire weather conditions are possible late this
evening and into tonight across eastern portions of the Northern
Coast Ranges, as a tightening surface pressure gradient coupled with
overlapping enhanced mid-level flow promotes increasingly gusty
surface winds amidst pockets of poor overnight RH recoveries. A fire
area may be needed in a future update if trends in guidance suggest
greater coverage of elevated fire weather conditions.

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

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SPC Day 2 Fire Weather Outlook

SPC Day 2 Fire Weather Outlook
          
Day 2 Fire Weather Outlook Image
Day 2 Fire Weather Outlook  
NWS Storm Prediction Center Norman OK
0259 PM CDT Sun Sep 22 2019

Valid 231200Z - 241200Z

Consensus among guidance exists that the LAX/TPH pressure gradient
will increase late Monday into early Tuesday morning. Accordingly,
high resolution guidance has forecast 15-25 mph winds in the higher
terrain of Los Angeles/Ventura counties. There is still uncertainty
with regard to how low overnight RH will drop in these areas as well
as how long these conditions will occur. Nonetheless, trends in
guidance suggest an increase in fire weather concerns for these
areas and elevated highlights have been introduced for that reason.

..Wendt.. 09/22/2019

.PREV DISCUSSION... /ISSUED 0130 AM CDT Sun Sep 22 2019/

...Synopsis...
A strong mid/upper-level trough -- and associated area of enhanced
mid-level flow -- is forecast to gradually move southeastward from
the Great Basin to the Desert Southwest Day 2/Monday.  

...Northern California...
Elevated to locally critical fire weather conditions are expected
Day 2/Monday across portions of the Sacramento Valley (especially
western portions of the valley) and adjacent North Coast Ranges, as
dry/gusty low-level northerly flow -- beneath the aforementioned
area of enhanced mid-level flow -- overlaps near critical minimum RH
values and at least marginally receptive fuels. Elevated fire
weather conditions may also persist into the overnight due to poor
RH recoveries and lingering gusty/breezy surface winds -- especially
in terrain favored areas of the North Coast Ranges. 

...Southern California...
While a combination of increasing offshore surface flow and poor
overnight RH recoveries may promote at least locally elevated fire
weather conditions late overnight Day 2/Monday, the uncertainty
regarding timing/coverage of any fire weather conditions precludes a
fire weather area at this time.

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

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