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FNUS28 KWNS 172137

Day 3-8 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0336 PM CST Sun Dec 17 2017

Valid 191200Z - 251200Z

An amplified, progressive synoptic pattern will aid in fostering
elevated to critical fire weather conditions in portions of the
Southwest and southern Rockies/Plains during the extended forecast
period.  The Plains/Rockies fire weather threat will be bolstered by
a gradually strengthening lee cyclone in the Rockies that will
migrate slowly southeastward along a stout cold front during the
D4/D5 time frame.  Farther west, strong northerly flow on the
upstream side of a vigorous mid-level disturbance will combine with
high pressure in the Great Basin to produce gusty surface winds from
D4/Wed through D5/Thu, with a lingering offshore gradient persisting
into at least D6/Fri.

...D4/Wed through D6/Fri - Central into Southern California...
The aforementioned synoptic features will result in strong wind
gusts developing in earnest beginning around D4/Wed evening and
persisting through D5/Thu.  Fuels in most of the area will remain
dry (especially in southern California) although some precipitation
may occur closer to the center of the track of the mid-level
disturbance over portions of central California.  Nevertheless,
low-level drying and an offshore component to surface winds across
the region will elevate fire weather concerns in most areas.  40%
probabilities have been introduced and/or expanded across much of
the region and this area will likely be reconfigured in the coming
days to identify areas that may eventually need critical upgrades.

Beyond D5/Thu evening, mid-level flow will decrease as the mid-level
disturbance migrates away from the area.  However, surface flow will
remain strong with an offshore component due to high pressure
lingering in the Great Basin.  Fire weather concerns will eventually
become more concentrated in areas of southern California from the
Santa Barbara area southeastward toward San Diego.  Beyond D6/Fri,
some uncertainty within the overall synoptic pattern exists,
precluding any highlights.

...D4/Wed into D5/Thu - Portions of the Southern Rockies and
An expansive dry sector will develop across the region on both days
in response to a strengthening surface cyclone over Colorado.
Elevated conditions will become common, with critical potential
dependent on specific corridors of stronger winds that will
eventually become better resolved with time.  Potential
precipitation in southern New Mexico/west Texas may also alter fuel
states, which may impact the extend of the fire weather threat in
those areas on D5/Thu.  Elevated fire weather conditions may also
extend as far east as central Oklahoma on D5/Thu pending eventual
location of a surface dryline during that afternoon.

..Cook.. 12/17/2017

...Please see for graphic product...

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