U.S. Day 1 Fire Weather Outlook
ZCZC SPCFWDDY1 ALL
FNUS21 KWNS 071649
Day 1 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
1149 AM CDT Mon Jul 07 2025
Valid 071700Z - 081200Z
...Central Nevada...
Increasing mid-level flow on the southeastern periphery of a cut off
low off the northern CA coast will overspread portions of the Great
Basin today. A very dry boundary layer with single digit relative
humidity and sustained south/southwest winds of around 15 mph will
support elevated fire weather conditions over portions of central
Nevada this afternoon. Otherwise, previous forecast (see below) for
isolated dry thunderstorms across far northern CA into south-central
OR remains consistent with latest short term model guidance.
..Williams.. 07/07/2025
.PREV DISCUSSION... /ISSUED 0158 AM CDT Mon Jul 07 2025/
...Synopsis...
A midlevel low off the northern/central CA coast will move slowly
northward through the period. Related midlevel ascent will
overspread northern CA into southern OR, aiding in the development
of isolated high-based thunderstorms over the higher terrain during
the afternoon. Deep inverted-V soundings with 0.5-0.75 inch PW will
favor dry thunderstorms, with an associated risk of
lightning-induced ignitions and gusty outflow winds atop receptive
fuels.
Farther south, enhanced southerly flow peripheral to the midlevel
low will overspread a well-mixed boundary layer across the Great
Basin. This will promote locally dry/breezy conditions, with locally
elevated fire-weather conditions possible over parts of
central/southern NV during the afternoon.
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U.S. Day 2 Fire Weather Outlook
ZCZC SPCFWDDY2 ALL
FNUS22 KWNS 071958
Day 2 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0258 PM CDT Mon Jul 07 2025
Valid 081200Z - 091200Z
...Northwest and Great Basin...
An approaching mid-level trough and associated increasing mid-level
west winds will introduce elevated fire weather conditions into the
Columbia Gorge/Basin and adjacent leeward slopes of the Cascades
Tuesday. A mid-level low off the coast of northern CA will provide
supportive dynamics for isolated thunderstorms across central OR.
Limited precipitation with these thunderstorms will increase fire
ignition potential amid receptive fuels primarily across the higher
terrain of central and east-central OR. Elevated fire weather
conditions atop dry fuels are still expected across much of central
and eastern NV and far western UT where southwest winds of 10-20 mph
and relative humidity in the 10-15% range will be collocated.
..Williams.. 07/07/2025
.PREV DISCUSSION... /ISSUED 0200 AM CDT Mon Jul 07 2025/
...Synopsis...
A midlevel low will gradually approach the northern CA coast as it
loosely phases with a stronger midlevel trough moving eastward
across British Columbia on Tuesday. Large-scale ascent preceding the
midlevel low will aid in isolated thunderstorm development along the
higher terrain of central OR. Around 0.7 inch PW and a deeply mixed
boundary layer will favor dry thunderstorms, with an associated risk
of lightning-induced ignitions and strong/erratic outflow winds. At
the same time, a belt of moderate-strong midlevel winds peripheral
to the trough in British Columbia will cross the Cascades. This will
promote dry/breezy downslope winds in the Columbia Basin, with the
strongest winds expected through the Cascade Gaps. Given
dry/receptive fuels, elevated fire-weather conditions are expected.
Farther south, moderate deep-layer southwesterly flow ahead of the
midlevel low will overspread a well-mixed boundary layer across
parts of central/southern NV, where elevated to locally critical
fire-weather conditions are expected.
U.S. Day 3-8 Fire Weather Outlook
ZCZC SPCFWDD38 ALL
FNUS28 KWNS 072200
Day 3-8 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0500 PM CDT Mon Jul 07 2025
Valid 091200Z - 151200Z
...Day 3/Wednesday...
Stronger west winds with the arrival of a mid-level short wave
trough and attendant cold front are expected across the Columbia
Basin where fuels remain dry. Although cooler temperatures and
slightly higher humidity arrive with the cold front, sustained west
winds of 15-25 mph will continue to support a fire weather threat
amid dry fuels across the Columbia Basin. A mid-level short wave
trough will translate over a broad ridge situated over the
Southwestern U.S. Collocation of ascent ahead of a mid-level jet max
and antecedent mid-level moisture should support isolated
thunderstorms with limited rainfall across southeastern
OR/southwestern ID on Day 3/Wednesday. The accelerated mid-level
flow on the southern periphery of the aforementioned short wave
along with a deep/well-mixed boundary layer will promote elevated
west-southwest winds across much of the Great Basin and portions of
southern Idaho. The breezy and very dry conditions support at least
a 40% probability for critical fire weather conditions across the
region amid an expected dry fuelscape.
...Day 4/Thursday...
The mid-level short wave edges eastward into the Southern Rockies
bringing elevated west winds to the Intermountain West and great
Four Corners region Day 4/Thursday. A 40% probability for critical
fire weather was introduced into southern UT and northern AZ where
fuels will go under several days of drying through midweek, becoming
more receptive to wildfire spread.
...Day 5-8/Friday-Monday...
Building heat is expected across much of the Western U.S. through
the weekend under an expanding mid-level ridge over southern CA
which will promote a limited wind threat across the region. Monsoon
moisture and associated thunderstorms will remain confined to
southern AZ and NM through the weekend.
..Williams.. 07/07/2025
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