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FNUS28 KWNS 232137

Day 3-8 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0436 PM CDT Tue May 23 2017

Valid 251200Z - 311200Z

A deep mid-level trough over the eastern U.S. will eject quickly
toward the western Atlantic through D5/Sat as another weaker,
lower-amplitude, and positive-tilt trough migrates into the
Intermountain West.  As this occurs, surface cyclogenesis will
commence over the central/southern Plains, with a low becoming
nearly stationary in the Oklahoma/Texas region and a surface front
becoming nearly stationary from the Plains east-northeastward to the
Mid-Mississippi Valley.  A `dry sector` will develop from a dryline
over central Texas westward into the southern Rockies and Southwest,
with sufficient flow and dry conditions for areas of elevated to
critical fire weather to develop through D5/Sat in those regions.
Additionally, dry northwesterly surface flow in portions of the
northern Plains (Montana into the Dakotas) will lead to locally
elevated conditions in those areas, although concerns about fuels
preclude any delineations for this region.

...D3/Thu through D5/Sat - Portions of the Southwest and Southern
Westerly surface flow will develop as a result of vertical mixing
processes and a favorable surface pressure gradient.  Single-digit
RH values will become common in much of Arizona and New Mexico as
well, with areas of drying fuels resulting from multiple days of
warm, dry conditions in the region.  Given the atmospheric
conditions expected during the D3/Thu and D4/Fri afternoon periods,
40% and 70% areas have been delineated for this forecast with the
expectation that enough fuels will have cured to support the
potential for rapid fire spread.  These areas (particularly the
70%/critical areas) will likely need to be reconfigured in later
forecasts to highlight specific areas that experience dry fuels in
conjunction with the critical atmospheric fire weather conditions.

Only a 40%/elevated fire weather area is included for the D5/Sat
period.  Continued dry surface conditions (and single-digit RH
values) will occur during peak heating, but models suggest that
surface winds should be weaker across the region, with the critical
fire weather threat becoming less widespread than on previous days.

..Cook.. 05/23/2017

...Please see for graphic product...

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