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
1055 AM CDT Thu Oct 17 2019

Valid 171700Z - 181200Z

...CRITICAL FIRE WEATHER AREA FOR NORTHWEST COLORADO AND
SOUTH-CENTRAL WYOMING...

Locally elevated conditions are likely to develop across portions of
southern Nevada and northern Arizona this afternoon ahead of the
approaching cold front. Otherwise, the forecast remains on track,
and please see the discussion below for more details.

..Nauslar.. 10/17/2019

.PREV DISCUSSION... /ISSUED 0131 AM CDT Thu Oct 17 2019/

...Synopsis...
Upper-level ridging will move through the Plains and into the
Mississippi Valley today. Broad cyclonic mid-level flow will
strengthen across the Great Basin into the central/northern Rockies.
At the surface, a lee trough will deepen in the northern High Plains
will lower pressure extending as far south as the southern High
Plains. In the Great Basin, a Pacific cold front will progress into
the central/southern portion of the Basin by the end of the period.
High pressure building in behind the front will increase offshore
flow potential across the western Transverse Ranges in southern
California.

...Southern Utah...western Colorado...southern/central Wyoming...
Elevated to critical fire weather conditions are expected as the
stronger mid-level flow overspreads the region. Surface winds will
be further enhanced by a deepening surface trough to the east.
Greatest threat for critical fire weather will occur in far
northwest Colorado and a small, adjacent portion of south-central
Wyoming. Here, winds of 20-25 mph will be collocated with 10-15% RH.
Critical conditions are also probable farther north into Wyoming,
but fuel loading or moisture levels become less favorable with
northward extent. Elevated conditions will occur surrounding the
critical from southern/central Utah into central Wyoming. These
conditions are not likely to occur in the higher terrain within the
highlighted area on account of cooler temperatures/higher RH.

...Southern Plains...
A broad area of elevated conditions are expected from the Sangre de
Cristo Mountains, northeast New Mexico, portions of Texas/Oklahoma
Panhandles, and onto the Plains of eastern Colorado and far western
Kansas. Marginally dry fuels will encounter 15-20+ mph winds with
10-20% RH during the afternoon as the surface trough deepens in the
lee of the Rockies. Strongest winds are most likely in northeast New
Mexico, but fuels are not receptive enough to warrant a categorical
upgrade to critical. Some guidance suggests elevated conditions may
occur portions of western Oklahoma. Fuels have continued to dry
here, but guidance varies widely in the placement of RH less than
20%. For now, will highlight the potential for locally elevated
conditions.

...Southern California...
Current SBA/SMX pressure gradient is stronger than model guidance
has forecast. However, RAWS/ASOS observations show RH remaining
above even elevated thresholds. Some high-resolution guidance
depicts near elevated conditions developing by late in the forecast
period as high pressure to the north continues to build in. While
elevated highlights were considered, RH values above 20% are still
too likely. Given the potential for strong winds, however, locally
elevated conditions remain possible.

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

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