669
FNUS21 KWNS 261700
FWDDY1

Day 1 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
1159 AM CDT Thu Sep 26 2024

Valid 261700Z - 271200Z

The primary change with this update was to expand the Elevated
highlights northwestward across portions of eastern MT. Here,
surface observations already show a warming post-frontal air mass
under mostly clear skies, and continued heating will result in 20-25
percent RH. These warm/dry conditions will overlap 20-25 mph
sustained west-northwesterly surface winds for a couple hours this
afternoon, and given dry fuels, elevated to locally critical
conditions are expected. For additional details, see the previous
discussion below.

..Weinman.. 09/26/2024

.PREV DISCUSSION... /ISSUED 1220 AM CDT Thu Sep 26 2024/

...Synopsis...
The pattern across the US on Thursday will be characterized by
Hurricane Helene moving inland and becoming absorbed into the
upper-level flow across the eastern US as a ridge of high pressure
continues to be in place across the western US. Across the northern
Rockies, a shortwave trough will traverse the northern periphery of
the ridge with a dry cold front sagging southward into the northern
Plains through the period. Ahead of the front, relative humidity
around 15-20 percent will be possible across portions of eastern
Wyoming into South Dakota. The frontal passage will bring an
increase in surface winds, with sustained winds around 20-25 mph.
There is some question as to what the duration of overlap will be
between the lower relative humidity and stronger wind speeds. HREF
probabilities of Elevated to Critical conditions remain generally
around 30-40 percent. Fuels across much of eastern Wyoming into
South Dakota are critically dry. Taking into account the possibility
of briefly Elevated to locally Critical conditions, an Elevated area
was included with this outlook given the uncertainty.

...Please see www.spc.noaa.gov/fire for graphic product...

$$