RSS Mesoscale Discussions from Storm Prediction Center
No watches are valid as of Sun Aug 31 00:54:02 UTC 2025.
No Mesoscale Discussions are in effect as of Sun Aug 31 00:54:02 UTC 2025.
SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0741 PM CDT Sat Aug 30 2025
Valid 310100Z - 311200Z
...NO SEVERE THUNDERSTORM AREAS FORECAST...
...SUMMARY...
Strong thunderstorms will be possible across parts of the southern
and central Plains this evening, but the chance for severe is low.
...DISCUSSION...
Northwesterly mid-level flow is evident on water vapor imagery over
much of the central and southern U.S. At the surface, a moist
airmass is in place over the southern and central Plains, where
dewpoints are mostly in the upper 60s and lower 70s F. Scattered
thunderstorms are ongoing across much of this airmass. Due to
relatively weak instability and deep-layer shear, along with limited
large-scale ascent, any severe threat is expected to remain
extremely localized this evening. Elsewhere across the continental
U.S., no severe threat is expected this evening into tonight.
..Broyles.. 08/31/2025
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SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0409 PM CDT Sat Aug 30 2025
Valid 011200Z - 071200Z
A closed mid/upper-level low, initially located just off the Pacific
Northwest coast at the start of Day 3/Monday, is forecast to begin
retrograding farther westward into the Pacific Ocean by Day
4/Tuesday. Meanwhile, an upper-level ridge is forecast to continue
quickly building north/northwestward across the Western US Day
3/Monday and persist over the area through late next week. A compact
mid/upper-level low is forecast to drift slowly north/northeastward
from the Pacific Ocean and overspread portions of central/northern
California Day 4/Tuesday and Oregon by Day 6/Thursday, while moving
along the western periphery of the ridge.
...Day 3/Monday: Northern California, the inland Northwest, and the
northwest Great Basin...
Lingering dry and breezy conditions are expected across wind-prone
portions of Northern California, the inland Northwest, and the
northwest Great Basin Day 3/Monday owing to enhanced flow associated
with the aforementioned closed low along the Pacific Northwest
coast. Current ensemble forecasts suggest wind speeds remaining
below critical thresholds on a large-scale basis, precluding
critical probabilities.
...Day 3/Monday - Day 6/Thursday: Northern California and the
Northwest...
Hot, dry, and unstable conditions are forecast to develop across
portions of Northern California and the Northwest Day 3/Monday and
persist through much of the week as the aforementioned upper-level
ridge builds into the area and a thermal trough strengthens. This
may lead to an increase in fire activity from recent holdovers and
also promote longer burn periods on any ongoing large fires.
Lightning potential may also increase across portions of northern
California into southern Oregon Day 4/Tuesday through Day
6/Thursday, as the aforementioned compact upper-low drifts northward
and increasing moisture interacts with a hot and unstable
atmosphere. Primary forecast challenge remains the evolution of the
low, with key differences still present in ensemble guidance
regarding how quickly the low moves northward. These differences are
enough to lower confidence in the timing, the location, and the
coverage probabilities of thunderstorms, which precludes the
introduction of dry thunderstorm probabilities at this time.
Nevertheless, with fuels becoming increasingly receptive early next
week, as drying intensifies with the upper-level ridge building into
the area, a dry thunderstorm area may be needed as guidance comes
into better agreement.
..Elliott.. 08/30/2025
...Please see www.spc.noaa.gov/fire for graphic product...
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