U.S. Day 1 Fire Weather Outlook
ZCZC SPCFWDDY1 ALL
FNUS21 KWNS 110540
Day 1 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
1240 AM CDT Fri Oct 11 2024
Valid 111200Z - 121200Z
...Synopsis...
A mid-level trough approaching the western U.S. coast will result in
modest west-southwesterly flow over the Great Basin throughout
Friday into Saturday. While the overall threat for significant
wildfire spread is low, daytime heating (and resulting
boundary-layer mixing) will drop relative humidity values to 10-15%,
and winds will reach 15-20 MPH. These conditions overlap with
modestly receptive fuels, with ERC values varying between the 80th
and 90th annual percentiles, warranting Elevated highlights across
eastern Nevada and western Utah.
..Halbert.. 10/11/2024
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U.S. Day 2 Fire Weather Outlook
ZCZC SPCFWDDY2 ALL
FNUS22 KWNS 110544
Day 2 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
1244 AM CDT Fri Oct 11 2024
Valid 121200Z - 131200Z
...Synopsis...
A mid-level trough progressing across the Pacific Northwest will
result in modest mid-level westerly flow across the Great Basin,
while east of the Rockies, the flow is predominantly northwesterly
with a stronger jet core moving from Canada into the northern Great
Plains. These mid-level features are responsible for two separate
Elevated highlights on Saturday: one across much of western Utah
into far eastern Nevada and northern Arizona, and the other
stretching from far southern North Dakota/Western Montana into far
northwestern Kansas.
...Great Basin...
Daytime heating and boundary-layer mixing will result in relative
humidity values of 10-15% and surface wind speeds of 15-20 MPH.
While the threat for significant wildfire spread is low, these
conditions overlap with modestly receptive fuels, and dry/windy
conditions the preceding day that will contribute to additional
curing of fuels.
...Northern and Central Great Plains...
Post-frontal dry/breezy conditions are expected across the northern
and central Great Plains, with the strongest winds (15-20 MPH)
expected further north into South Dakota closer to the mid-level jet
core. While the magnitude of surface winds further south remains
somewhat uncertain, much of the central and northern Great Plains
fuels have ERC values exceeding the annual 98th percentile. Given
the receptiveness of fuels to wildfire spread, Elevated highlights
were extended southward into Nebraska and northern Kansas where
winds could reach 15 MPH.
..Halbert.. 10/11/2024
U.S. Day 3-8 Fire Weather Outlook
ZCZC SPCFWDD38 ALL
FNUS28 KWNS 102058
Day 3-8 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0358 PM CDT Thu Oct 10 2024
Valid 121200Z - 181200Z
Mid-level ridging over the western and central US is forecast to
slowly breakdown heading into the weekend as a series of West Coast
troughs and increasingly strong flow aloft develop. Strong high
pressure will shift eastward and weaken as troughing develops over
the eastern third of the US. A cold front should move through the
Rockies and northern Plains early this weekend ahead of a second,
stronger, front moving out of southern Canada and across the central
US early next week. Dry and breezy conditions, supporting a low-end
risk for fire-weather conditions, are possible across the Plains,
Midwest and Great Basin through this weekend and into next week.
More widespread fire-weather concerns could develop midweek next
week.
...Plains and Midwest...
As the ridge aloft weakens, stronger mid-level flow will gradually
move southward, first across the norther Plains and Upper Midwest,
before developing over much of the central US. Dry and breezy
conditions are possible behind and ahead of the aforementioned cold
front through D3/D4 Sat/Sun, though the exact coverage and duration
remains unclear. Still, the lack of recent rainfall and stronger
winds suggests some fire-weather risk could evolve. Gusty southerly
winds and very warm temperature are also possible over parts of the
southern High Plains supporting some risk for locally elevated
fire-weather potential given receptive fuels.
Fire-weather concerns appear likely to increase early to midweek
next week behind the second cold front as a strong area of high
pressure develops over the eastern US. Breezy northerly winds are
possible through early next week ahead of a strong area of low
pressure expected to develop over the southern Plains. Elevated to
critical fire-weather conditions are possible across the Plains and
central US, given the overlap with very dry fuels and little recent
rainfall. However, model guidance varies substantially on the timing
and intensity of conditions.
...Great Basin...
Breezy winds and low RH are possible over portions of the eastern
Great Basin this weekend. Stronger flow aloft associated with
western US troughing and the cold frontal passage could support
another period of dry and windy conditions through early next week.
Forecast certainty of widespread dry and breezy conditions is low,
but Elevated highlights could be needed in future outlooks should
confidence increase.
..Lyons.. 10/10/2024
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