ZCZC SPCFWDDY2 ALL
FNUS22 KWNS 161924
Day 2 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0224 PM CDT Mon Jul 16 2018
Valid 171200Z - 181200Z
Elevated and locally critical fire weather conditions (sustained
west-southwest surface winds of 15-20 mph; RH values of 10-30%) are
expected to develop in/around the Columbia River Gorge/Basin and
along/east of the Cascades from central Washington to central
Oregon. Stronger winds are expected to develop as the pressure
gradient increases between onshore flow west of the Cascades and the
thermal trough east of the Cascades and overlap with a hot/dry air
mass. Elevated fire weather conditions should also develop tomorrow
afternoon/evening across portions of the Snake River Plain as
stronger mid-level winds mix to the surface (15-20 mph) associated
with the passage of an upper-level shortwave trough and overlap with
RH values of 10-20%. Any increase of winds/drying could exacerbate
fire activity given the recent lightning and fire ignitions across
some of these areas.
Additionally, the isolated dry thunderstorm area was slightly
modified based on latest guidance, but remains on track.
.PREV DISCUSSION... /ISSUED 0202 AM CDT Mon Jul 16 2018/
Zonal flow will persist across the Pacific Northwest during the Day
2/Tuesday period. At the surface, a thermal low will develop east of
the Cascades. Mid-level moisture attributed to the monsoon will also
hover over the Great Basin into the Pacific Northwest.
...Central/eastern Washington and Oregon...
A very hot surface airmass is expected to develop east of the
Cascades during the afternoon on Day 2/Tuesday, promoting the
development of a thermal low/trough. A weak pressure gradient will
result from the trough, inducing downslope flow to the lee of the
Cascades. Surface winds are expected to reach up to 15-20 mph during
the late afternoon in the presence of 100 F temperatures and 10-15%
RH. With receptive fuels present, an elevated delineation was made
where windy and hot/dry conditions may support an environment
favorable for fire spread.
...Idaho/Montana border into far west Wyoming...
Isolated thunderstorms are expected to develop along the periphery
of greater mid-level moisture associated with the monsoon. An
isolated dry thunderstorm delineation was added where the greatest
confidence in dry strikes would be, in addition to faster storm
motions due to a belt of stronger mid-level flow embedded within the
larger scale zonal pattern. Fuels have also become at least
marginally receptive to fire spread.
...Please see www.spc.noaa.gov/fire for graphic product...
CLICK FOR DAY 2 FIREWX AREAL OUTLINE PRODUCT (KWNSPFWFD2)