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U.S. Day 1 Fire Weather Outlook
ZCZC SPCFWDDY1 ALL
FNUS21 KWNS 141648
Day 1 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
1148 AM CDT Mon Jul 14 2025
Valid 141700Z - 151200Z
...CRITICAL FIRE WEATHER AREA FOR CENTRAL WASHINGTON...
...Central/Northeastern Utah and Northwestern Colorado...
A weak upper-level wave evident in water vapor imagery will move
through northern Utah today. Slightly increased mid-level flow on
the southern periphery of the wave will support enhanced dry
downslope flow into the Uinta Basin and along and east of the
central Utah mountain chain. Sustained winds of 10-15 mph along with
10-15 percent relative humidity will result in a period of elevated
fire weather conditions over dry fuels where ERC values are around
the 97th percentile.
Otherwise, no major changes to previous forecast (see below) for the
Northwest, Great Basin or Snake River Plain highlights.
..Williams.. 07/14/2025
.PREV DISCUSSION... /ISSUED 0138 AM CDT Mon Jul 14 2025/
...Synopsis...
A mid-level trough will bring a belt of enhanced westerly flow aloft
across portions of the Pacific Northwest today. A period of Elevated
to Critical fire weather conditions can be expected across the
Columbia River Basin in Oregon and Washington and in the Snake River
Plain in Idaho. The trough will also promote dry thunderstorm
development across the Great Basin.
...Cascades and Columbia River Basin...
Relative humidity reductions to 15-20 percent will combine with west
winds around 15 mph promoting elevated fire weather concerns for the
Columbia River Basin through Monday afternoon. A considerable wind
shift is expected with the dry cold front passage beginning early
afternoon across the Okanagan Valley before reaching the Columbia
River by evening. Although relative humidity will rise behind the
front, a few hours of sustained north winds of 20-30 mph will create
Critical fire weather concerns and could significantly impact
existing active or new fires Monday.
...Snake River Plain...
Relative humidity reductions to 15-20 percent will combine with
westerly winds around 10-15 mph (locally higher) through Monday
afternoon. Locally stronger winds may bring near Critical to
Critical conditions, however the localized nature precludes
inclusion of a Critical area at this time.
...Dry Thunderstorms...
Forcing for ascent with the upper-level trough will allow for high
based convection to develop across portions of the northern Great
Basin. Primarily mid-level moisture will overspread a very dry and
warm boundary layer, with little to no precipitation and storm
motions around 10-20 mph. This in combination with critical fuels
supports maintaining and area of isolated dry thunderstorm chances
across northern Nevada into southeastern Oregon, southern Idaho, and
far northeastern Nevada.
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U.S. Day 2 Fire Weather Outlook
ZCZC SPCFWDDY2 ALL
FNUS22 KWNS 141956
Day 2 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0256 PM CDT Mon Jul 14 2025
Valid 151200Z - 161200Z
...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF EASTERN NEVADA INTO
WESTERN UTAH AND NORTHERN ARIZONA...
...Dry Thunderstorms...
An expansive area of isolated dry thunderstorms across the was
maintained for this update, with only slight northward adjustments
to highlights into north central Nevada as well as southeastern ID
and far western WY given latest model guidance consensus. An
advancing mid-level trough into the northwest and attendant
increased mid-level flow will support faster thunderstorm motions
particularly across central and northeastern NV Tuesday, with
northeast trajectories of 20-30 mph. This will limit rainfall
residence time and increase lightning ignition efficiency over dry
fuels.
...Great Basin...
Enhanced westerly flow over western Nevada associated with the an
encroaching mid-level trough over a deeply mixed boundary layer will
promote west winds approaching 20 mph across northwestern NV.
Relative humidity combined with higher winds will support an
elevated fire weather threat amid dry fuels. Higher winds under a
similarly dry boundary layer will bring critical fire weather
conditions to portions of eastern NV, southwestern UT and the
Arizona Strip.
..Williams.. 07/14/2025
.PREV DISCUSSION... /ISSUED 0144 AM CDT Mon Jul 14 2025/
...Synopsis...
A deepening mid-level wave will bring an increase in winds and
potential for dry thunderstorms across the Great Basin on Tuesday.
Elevated to Critical conditions can be expected in portions of
eastern Nevada, western Utah, northern Arizona and southern Idaho.
...Eastern Nevada, western Utah, northern Arizona...
Increasing southwesterly flow around 10-20 mph will overlap with
afternoon relative humidity reductions to around 10-15 percent on
Tuesday afternoon. The best overlap of Critical winds and relative
humidity appears to be across eastern Nevada into western Utah.
Further south into northern Arizona and the Arizona Strip, winds may
be at or just below Critical thresholds. However, ongoing fires with
a history of erratic fire behavior warrant inclusion into the
Critical area. Gusty and erratic winds from nearby thunderstorms
will also be possible.
...Dry Thunderstorms...
Isolated dry thunderstorms will be possible on the periphery of
deeper monsoonal moisture across portions of northern Arizona into
western Colorado, Utah, far southern Idaho, western Wyoming, and
Nevada. Within these regions, PWs generally around 0.25-0.50" are
expected with moisture remaining primarily mid-level with drier
boundary layer conditions below. This will promote high based
convection with little precipitation amid faster storm motions with
the mid-level trough passage. Fuels within these regions are
receptive to ignition and as such an isolated dry thunder area was
maintained with this outlook.
U.S. Day 3-8 Fire Weather Outlook
ZCZC SPCFWDD38 ALL
FNUS28 KWNS 132159
Day 3-8 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0459 PM CDT Sun Jul 13 2025
Valid 151200Z - 211200Z
...Day 3/Tuesday...
A mid-level wave translating eastward through the Northern Rockies
will bring widespread and impactful fire weather threats to portions
of the West. Breezy winds and low relative humidity will be
prevalent across the Snake River Plain, interior southern CA and
especially the Great Basin where a 70 percent critical probabilities
were introduced into eastern NV/western UT. A dry boundary layer in
place coupled with enhanced mid-level flow will support surface
winds of 15-25 mph and low relative humidity over dry fuels.
Increasing mid-level monsoon moisture over the Great Basin and
Intermountain West with at least some upper-level support from the
passing trough to the north will provide for faster moving showers
and thunderstorms with limited rainfall across central/northeast NV,
much of UT and into the Four Corners area. Receptive fuels will
promote lightning ignitions with 10 percent probability of dry
thunderstorms introduced for Day 3/Tuesday.
...Day 4/Wednesday...
Residual breezy and dry conditions across southern NV/southwestern
UT will bring a continued fire weather threat to the area on Day
4/Wednesday. A few high-based thunderstorms are expected across the
higher terrain in eastern NV and much of UT but higher thunderstorm
coverage will be along and east of the Continental Divide.
...Day 5-8/Thursday-Sunday...
Higher forecast confidence exists for a mid-level low over Baja
California to move into southern CA by the end of the week. This
will aid in the northward transport of deeper monsoon moisture, with
precipitable water values in the 0.7-1.0 inch range, into the Desert
Southwest and Intermountain West through the weekend. A broad area
of mixed wet/dry thunderstorms are likely across much of the
Intermountain West and Great Basin. Farther northwest, another
upper-level trough moving into the Pacific Northwest could
reintroduce a fire weather threat for interior WA/OR for the weekend
where rainfall deficits and dry fuels persist, particularly across
the Columbia Basin. Some uncertainty in timing of the trough
precludes introductions of critical probabilities at this time.
..Williams.. 07/13/2025
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