U.S. Day 1 Fire Weather Outlook
ZCZC SPCFWDDY1 ALL
FNUS21 KWNS 261633
Day 1 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
1133 AM CDT Fri Jul 26 2024
Valid 261700Z - 271200Z
The main change to this outlook was to add isolated dry thunderstorm
highlights to portions of central and northern Utah. Thunderstorms
from prior days may have tempered fuels to a degree. Nonetheless, a
mix of wet and dry thunderstorms are expected later this afternoon
and tonight, and some of these storms may pass over fuel beds that
have experienced minimal rainfall. Otherwise, the previous forecast
(see below) remains on track, with minor changes made to existing
highlights to reflect the latest guidance consensus.
..Squitieri.. 07/26/2024
.PREV DISCUSSION... /ISSUED 0145 AM CDT Fri Jul 26 2024/
...Synopsis...
Two primary synoptic features will be responsible for bringing
elevated fire weather conditions to portions of the Northwest. A
mid-level trough progressing eastward across the Bay Area and into
the northern Great Basin will bring elevated fire weather conditions
to portions of northeastern California, southern Oregon, and the
Snake River Plain of Idaho, while an exiting jet streak associated
with a trough centered over Saskatchewan will bring elevated fire
weather conditions to portions of northern Montana. These elevated
highlights are primarily confined to where the dry and windy
conditions correspond to regions where wetting rainfall has not
impacted fuels over the last several days.
...Pacific Northeast and the Snake River Plain...
Portions of northeastern California into southwestern Oregon, as
well as the eastern portions of the Snake River Plain in Idaho, are
expected to have dry and windy conditions that overlap with
receptive fuels. Some wetting rainfall has occurred over the last
few days, but with recent lightning activity and some pockets of
receptive fuels, some potential for wildfire spread exists with any
previously existing fires and lightning ignitions.
...Northern Montana...
Some uncertainty exists about the receptiveness of fuels over
western portions of the highlight area due to recent wetting
rainfall, but generally, 20-25 MPH winds and relative humidity
values of 10-15% will overlap with pockets of receptive fuels.
...Dry Thunder...
Portions of the Great Basin and far southern Montana may see a mix
of dry and wet thunderstorms. Given the uncertainty in precipitation
efficiency, and recent wetting rainfall over much of the area, dry
thunder highlights have been withheld at this time.
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U.S. Day 2 Fire Weather Outlook
ZCZC SPCFWDDY2 ALL
FNUS22 KWNS 261935
Day 2 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0235 PM CDT Fri Jul 26 2024
Valid 271200Z - 281200Z
The main change to the Day 2 Fire Weather Outlook Update was to
expand isolated dry thunderstorm highlights westward to include
portions of western Idaho into eastern Oregon. The lack of
upper-level support and shallow buoyancy suggests that thunderstorm
development in these areas should be more sparse compared to places
farther east. Still, fuel beds in these areas remain receptive to
fire spread wherever dry strikes may occur, necessitating the
expanse of isolated dry thunderstorm highlights this outlook.
Otherwise, the previous forecast (see below) remains on track.
..Squitieri.. 07/26/2024
.PREV DISCUSSION... /ISSUED 0158 AM CDT Fri Jul 26 2024/
...Synopsis...
As a mid-level trough progresses eastward from California into the
northern Great Basin on Saturday, isolated dry thunderstorms are
expected across portions of eastern Idaho, southwestern Montana,
western Wyoming, and portions of far northern Utah. This trough is
also expected to bring dry and windy conditions to much of southern
Nevada into southwestern Utah.
...Dry Thunder...
An approaching trough from California is expected to bring chances
for isolated dry thunderstorms to portions of Idaho, Montana,
Wyoming, and Utah. Recent wetting rainfall could potentially limit
some lightning ignitions, but pockets of receptive fuels still
remain across much of the highlight area. Dry boundary-layer
profiles will support gusty thunderstorm outflow that could
contribute to wildfire spread with any lightning based ignitions.
...Southern Great Basin...
Relative humidity of 5-10% and wind speeds of 25-30 MPH are expected
across southern Nevada into southwestern Utah, exceeding the
meteorological criteria for critical conditions. However, there is
uncertainty in the receptiveness of fuels to wildfire spread due to
recent significant wetting rainfall, precluding the inclusion of
critical highlights at this time.
U.S. Day 3-8 Fire Weather Outlook
ZCZC SPCFWDD38 ALL
FNUS28 KWNS 262041
Day 3-8 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0341 PM CDT Fri Jul 26 2024
Valid 281200Z - 031200Z
Multiple mid-level impulses will traverse the northwestern U.S. Days
3-5 (Sunday-Tuesday) before upper riding builds over the western and
central CONUS through most of next week. The passing mid-level
impulses will encourage dry and occasionally breezy conditions
across areas east of the Cascades into the Great Basin. The best
chance for Elevated equivalent meteorological surface conditions
will be over southeast Nevada into Utah on Sunday, where 40 percent
Critical probabilities have been introduced. These conditions may
persist into Monday across the same areas, as well as the lee of the
Cascades with the progression of a mid-level impulse. A stray dry
thunderstorm or two may also occur ahead of this impulse across the
northern Rockies somewhere in the Monday-Tuesday time frame, though
coverage and available buoyancy appears too marginal for dry
thunderstorm probabilities this outlook. Relatively quiescent fire
weather conditions are expected through the rest of next week across
the Interior West as mid-level impulses clear the region and upper
ridging becomes established.
..Squitieri.. 07/26/2024
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