Fire Weather Outlook Discussion
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FNUS22 KWNS 190754

Day 2 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0254 AM CDT Thu Oct 19 2017

Valid 201200Z - 211200Z

A large-scale trough is forecast to move from the Pacific Northwest
into the Rockies/High Plains by the end of Day 2/Friday. As this
occurs, a mid-level speed maximum will overspread the northern
Rockies into the northern High Plains. Additionally, low pressure
over Alberta/Saskatchewan will move eastward toward Manitoba, while
a trailing cold front shifts from the Great Basin toward the
Rockies/High Plains.

...Eastern Wyoming...
Strong/gusty southwesterly pre-frontal downslope surface winds are
forecast to develop by afternoon, as the aforementioned mid-level
speed maximum nudges into the area. A relatively deep mixed layer
will reside beneath the stronger flow, which will promote efficient
mixing, with sustained surface wind in excess of 20 mph expected.
Despite critical surface winds, the latest ensemble/deterministic
guidance continues to suggest that the degree of low-level drying
will be less than previous days -- owing in part to increasing
low-level moisture. Current indications are that minimum RH values
will remain above Critical thresholds (i.e., greater than 15%), with
minimum RH values around 15-25%. However, guidance may not be
capturing the full extent of the low-level warming/drying associated
with the downslope flow. Thus, while a Critical area was not
introduced at this time, one would be needed in future updates if
trends in guidance suggest greater low-level warming/drying.
Regardless, the strength of the low-level wind field coupled with at
least modest reductions to RH values supports maintaining the
ongoing Elevated fire weather area (with only modest adjustments).

..Elliott.. 10/19/2017

...Please see for graphic product...

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