Fire Weather Outlook Discussion
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FNUS22 KWNS 181948

Day 2 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0248 PM CDT Wed Oct 18 2017

Valid 191200Z - 201200Z

Modest expansions have been made to the elevated areas across parts
of MT and central/eastern WY for Day 2/Thursday based on latest
short-term model guidance. Uncertainty regarding sufficient duration
of critically reduced RH values precludes the introduction of
critical delineations for now. See the previous discussion below for
more information.

..Gleason.. 10/18/2017

.PREV DISCUSSION... /ISSUED 0146 AM CDT Wed Oct 18 2017/

Broad cyclonic flow is expected to return across the western United
States Day 2/Thursday, as a large-scale trough amplifies across the
Pacific Northwest. At the surface, low pressure over central Alberta
is forecast to shift slowly eastward, reaching western Saskatchewan
by the end of the forecast period. Meanwhile, a trailing cold front
should move from the Pacific Northwest out into the northern

...Central/Eastern Montana...
This area will reside beneath enhanced mid-level southwesterly flow
associated with the aforementioned trough. By afternoon, efficient
boundary-layer mixing is expected to foster sustained southwesterly
surface winds of 15-20 mph in an area of reduced RH values of around
20-25%. These meteorological conditions will occur in an area of
receptive fuels (especially fine fuels) -- partly owing to the lack
of recent precipitation and ongoing drought conditions -- and will
promote Elevated fire weather conditions for at least a few hours
during the afternoon.

...Central/Northeast Wyoming...
Elevated fire weather conditions are also expected across portions
of WY, where RH values near 15-20% are forecast to occur in
conjunction with receptive fuels and sustained southwesterly surface
winds of around 15-25 mph. While locally critical conditions may
develop across portions of the area, large model spread regarding
the degree of warming/drying in the low levels precludes upgrading
to Critical at this time. If trends in guidance suggest greater
warming/drying, then an upgrade would be needed in future updates.

...Please see for graphic product...

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