Storm Prediction Center Day 1 Fire Weather Outlook
Created: Fri Jul 20 16:28:02 UTC 2018 (
| 
)
Storm Prediction Center Day 1 Fire Weather Outlook
Created: Fri Jul 20 16:28:02 UTC 2018 (
| )
| |||||||||
Click for Day 1 FireWX Areal Outline Product
ZCZC SPCFWDDY1 ALL
FNUS21 KWNS 201626
Day 1 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
1126 AM CDT Fri Jul 20 2018
Valid 201700Z - 211200Z
An elevated area was added for portions of far southwest
Oregon/northwest California where gusty north-northeast winds
(sustained 15-20 mph) will overlap with RH values of 15-25% this
afternoon/evening. The elevated area over central Oregon was
expanded farther south as a dry cold front should increase winds
this evening as it passes through the region. The ongoing fire
activity within these two elevated areas are likely to be
exacerbated by these dry/windy conditions and antecedent dry fuels.
The isolated dry thunderstorm area was expanded southward as
monsoonal moisture continues slowly moving northward via latest
surface/upper-air observations and water vapor imagery.
Overall, the forecast looks on track and please see discussion below
for more details.
..Nauslar.. 07/20/2018
.PREV DISCUSSION... /ISSUED 0204 AM CDT Fri Jul 20 2018/
...Synopsis...
A long-wave upper-level trough will move into the Pacific Northwest
today. In the meantime, an upper-level ridge will build across the
Front Range of the Rockies. An area of enhanced 40 to 50 knot
mid-level flow will develop across much of the Pacific Northwest and
could lead to several areas of elevated fire weather concern. In
addition, thunderstorms will develop across much of the Desert
Southwest, Great Basin, and Colorado Rockies. Some of these
thunderstorms will be on the drier side along the northern and
western periphery of the richer moisture.
...Columbia River Basin...
Downslope flow and deep mixing will lead to sustained winds around
15 mph across much of the Columbia River Basin. These winds,
combined with RH values of 15 to 20 percent, will lead to elevated
fire weather conditions. Wind speeds may be slightly higher in some
of the gaps in the Cascades, but the marine influence west of the
Cascades will lead to slightly higher RH values (25 to 30 percent)
in these locations.
...Southern Idaho...
Sustained winds will approach 15 mph during the afternoon today as
deep mixing transports stronger mid-level winds towards the surface
across much of the Snake River Valley into portions of the
Bitterroot Mountains. RH values will be 10 to 15 percent across much
of this area leading to elevated fire weather conditions.
...Northern Montana...
Downslope flow and deep mixing will lead to increasing surface winds
into the afternoon east of the Lewis Range. In addition, RH values
will drop to the 15 to 20 percent range. This will lead to elevated
fire weather conditions for at least a few hours on Friday.
...Eastern California into the northern Great Basin...
An area of dry thunderstorms is possible along the periphery of the
greater monsoon moisture from far eastern California across northern
Nevada and Utah and into far southwest Wyoming. Kept the isolated
dry thunderstorm delineation to areas which have seen mostly limited
rainfall (< 0.25") over the past 7 days where PWAT values are less
than an inch and storms are expected.
...Southern Plains...
A heat wave in the southern Great Plains will lead to dry conditions
during the afternoon hours for much of west eastern New Mexico, West
Texas, and western and central Oklahoma. RH values are expected to
drop into the 15 to 20 percent range during the afternoon with an
increasing surface wind. Southerly surface winds will strengthen to
around 15 mph. This combination of gusty surface winds and low
relative humidity values warrants elevated fire weather concerns
across much of the southern High Plains into western and central
Oklahoma. While some of this area has seen significant rainfall over
the past 7 days, coverage of these storms has been spotty, and hot
weather the past few days has led to significant drying of fine
fuels.
...Please see www.spc.noaa.gov/fire for graphic product...