ZCZC SPCFWDDY1 ALL
FNUS21 KWNS 161659
Day 1 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
1159 AM CDT Mon Jun 16 2025
Valid 161700Z - 171200Z
...CRITICAL FIRE WEATHER AREA FOR PARTS OF SOUTHERN
NEVADA...SOUTHWESTERN UTAH AND NORTHWESTERN ARIZONA...
...Great Basin and Southwest...
Current surface observations show single digit relative humidity
across the southern Great Basin and parts of the Southwest.
Increasing mid-level flow ahead of an upper-level trough coupled
with a very dry/well-mixed boundary layer will promote sustained
surface winds of 20-25 mph across a corridor from southern Nevada,
northwestern Arizona and much of southern Utah with critical
highlights maintained amid the very low relative humidity regime and
dry fuels. Elevated fire weather concerns continue for a broader
area of the Great Basin and Southwest as the upper-level trough
translates eastward through the region. Otherwise, forecast remains
largely on track.
..Williams.. 06/16/2025
.PREV DISCUSSION... /ISSUED 0158 AM CDT Mon Jun 16 2025/
...Synopsis...
A midlevel trough will advance eastward from the West Coast across
parts of the Great Basin/Intermountain West today. Within the base
of the trough, moderate deep-layer westerly flow will overspread the
Great Basin, while a weak surface low/trough evolves over the Lower
CO River Valley.
...Southern NV into Southwest UT and far Northwest AZ...
Along the southern periphery of mid/high-level clouds preceding the
midlevel trough, strong diurnal heating of a warm/dry antecedent air
mass will result in a deeply mixed boundary layer across the
southern Great Basin. The deep mixing into the enhanced flow aloft,
along with a tightening pressure gradient peripheral to the surface
low/trough, will yield single-digit RH and 20-25 mph sustained
southwesterly surface winds (with higher gusts) across southern NV,
southwest UT, and far northwest AZ. Given increasingly dry fuels
across the region, critical fire-weather conditions are expected.
Farther north, modest westerly flow aloft across the Cascades will
contribute to locally dry/breezy downslope flow into the Columbia
Basin, where elevated fire-weather conditions are forecast.
U.S. Day 2 Fire Weather Outlook
ZCZC SPCFWDDY2 ALL
FNUS22 KWNS 162000
Day 2 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0300 PM CDT Mon Jun 16 2025
Valid 171200Z - 181200Z
...CRITICAL FIRE WEATHER AREA FOR FAR EASTERN ARIZONA AND WESTERN
NEW MEXICO...
An upper-level short wave trough and increased mid-level winds will
continue to bring Elevated to Critical fire weather conditions to
the portions of the Southwest Tuesday. Latest model guidance
consensus shows a slight northeastward push of stronger
west-northwest winds into northwestern New Mexico for Tuesday.
Sustained wind speeds of 15-25 mph combined with RH below 10 percent
will promote Critical fire weather conditions within dry fuels.
Critical highlights were nudged northward to cover this fire weather
threat. Otherwise, previous forecast remains on track.
..Williams.. 06/16/2025
.PREV DISCUSSION... /ISSUED 0159 AM CDT Mon Jun 16 2025/
...Synopsis...
Within the base of a midlevel trough advancing eastward from the
Great Basin into the central Rockies, moderate deep-layer westerly
flow will overspread the Southwest during the afternoon. In response
to this feature, a lee cyclone will deepen over the central High
Plains.
...Western NM and Eastern AZ...
Deep boundary-layer mixing into the enhanced flow aloft, coupled
with a tightening pressure gradient peripheral to the deepening lee
cyclone, will contribute to an expansive area of single-digit RH and
20 mph sustained westerly surface winds across western NM and
eastern AZ. These dry/windy conditions atop increasingly dry fuels
will lead to critical fire-weather conditions during the afternoon.
U.S. Day 3-8 Fire Weather Outlook
ZCZC SPCFWDD38 ALL
FNUS28 KWNS 162159
Day 3-8 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0459 PM CDT Mon Jun 16 2025
Valid 181200Z - 241200Z
...Day 3/Wednesday...
An upper-level short wave with attendant mid-level wind maxima will
promote breezy downslope/gap winds to the Columbia Basin where dry
fuels remain supportive of fire spread. Meanwhile, a broad ridge
axis roughly aligned along the Continental Divide will support above
normal temperatures for much of the West aiding in drying fuels
ahead of a stronger upper-level trough for the latter part of the
week.
...Day 4-6/Thursday-Saturday...
A potent upper-level trough and attendant stronger mid-level flow
will impact the western U.S. beginning on Day 4/Thursday introducing
a broad fire weather threat into the Great Basin and portions of the
Southwest. Considerable southwest surface winds of 20-30 mph and
very low relative humidity will coincide with dry fuels to promote
wildfire spread (including potential expansion of existing wildfire
footprints) across the region. Critical probabilities were added to
northwestern Nevada as well as southeastern Nevada and southwest
Utah. Primary fire weather threat expands eastward into Utah and
western Colorado on Day 5/Friday as upper-level trough shifts/nudges
eastward. Model guidance consensus suggests a deceleration of
eastward advancement of main trough axis by Day 6/Saturday, allowing
enhanced mid-level flow to remain over portions of the Four Corners
and Southwest into the weekend, while the Pacific Northwest
experiences some relief with cooler temperatures and some rainfall.
In addition, dry post-frontal winds should increase the fire weather
threat across the California Central Valley where a Critical 40
percent probability area has been maintained.
...Day 7-8/Sunday-Monday...
The multi-day fire weather event could linger into early next week
around the Four Corners region as a troughing pattern persists
across the Western U.S. However, decreasing mid-level flow as the
upper-level trough diffuses should limit magnitude of winds although
dry conditions and warm temperatures are still a high likelihood.
..Williams.. 06/16/2025
