Fire Weather Outlook Discussion
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FNUS22 KWNS 171920

Day 2 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0219 PM CDT Thu Aug 17 2017

Valid 181200Z - 191200Z

No appreciable changes were made to the Day 2/Friday forecast, with
elevated fire weather conditions developing during the afternoon
across portions of northern OR into central/eastern WA and also
across MT. Across these areas, dry westerly flow of 15-20 mph
juxtaposed with RH values of 10-20% and receptive fuels will act to
enhance the potential for fire spreads. See previous discussion
below for further information.

..Elliott/Jirak.. 08/17/2017

.PREV DISCUSSION... /ISSUED 0305 AM CDT Thu Aug 17 2017/

A rather strong mid/upper trough is expected to move eastward from
British Columbia into the Canadian Prairie provinces on Friday. In
conjunction with this trough, a surface low is expected to move
across southern AB/SK, with a surface trough extending southward
into portions of the northern Rockies/High Plains. Continued warming
and drying is expected across most of the interior Northwest into
the northern Rockies and High Plains, leading to an elevated fire
weather threat where winds are sufficient.

Modest westerly flow will result in continued warming/drying across
MT on Friday, and critically low RH is possible over much of the
state during the afternoon. The primary uncertainty regarding the
fire weather forecast is whether wind speeds will be sufficient for
at least an elevated threat. While the region will only be glanced
by stronger flow associated with the trough to the north, at this
time it appears sufficient flow will exist at the top of the
boundary layer to support sustained winds of 15-20 mph (with higher
gusts) over much of MT. Combined with minimum RH values of 10-20%
and receptive fuels, these winds appear sufficient for an elevated
fire weather threat.

...Portions of Northern OR...Central/Eastern WA...
Warm, dry, and breezy conditions are expected across portions of the
Columbia Gorge and in the lee of the Cascades across WA and northern
OR. While wind speeds may be somewhat marginal, the potential exists
for sustained winds exceeding 15 mph to combine with RH values of
10-20%, resulting in an elevated fire weather threat.

...Please see for graphic product...

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