Day 3 Convective Outlook  
NWS Storm Prediction Center Norman OK
0228 AM CDT Fri Oct 09 2026

Valid 111200Z - 121200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF
THE CAROLINAS INTO THE DELMARVA AND ACROSS PARTS OF THE LOWER
COLORADO VALLEY...

...SUMMARY...
Isolated severe storms capable of damaging wind gusts and perhaps a
few tornadoes appear possible over portions of the Carolinas into
the Delmarva Sunday into Sunday evening, and parts of the lower
Colorado Valley mainly Sunday morning.

...Synopsis...

A mid/upper-level low over KY/TN Sunday morning is forecast to
evolve into an open wave within a broader-scale trough progressing
through the central and southern Appalachians toward the Atlantic
Coast. Elsewhere, the remnants of Tropical Storm Rachel initially
over southern CA will become increasingly sheared within a broad
belt of enhanced midlevel flow extending from the Desert Southwest
into the central Rockies. At the surface, an area of low pressure
will develop from KY into the upper OH Valley with secondary
cyclogenesis forecast on Sunday afternoon in the lee of the Blue
Ridge over central VA. That cyclone will be collocated with a
surface trough advancing east through the Piedmont and Coastal Plain
and a warm front lifting north through the southern Mid-Atlantic.


...Delmarva into the Carolinas...

Considerable strengthening of the deep-layer wind field is forecast
on Sunday in advance of the midlevel trough. However, considerable
cloud cover and areas of precipitation appear likely to limit air
mass destabilization within the poleward-expanding warm sector.
Nonetheless, boundary-layer dewpoints in the upper 60s to mid 70s
will support pockets of modest instability, especially in areas
where cloud breaks may occur. And given the presence of relatively
strong low-level and deep-layer shear, a conditional risk for severe
storms capable of damaging winds and perhaps a few tornadoes will
exist Sunday into Sunday evening. Higher severe weather
probabilities may be required in later forecasts if subsequent model
data indicate greater instability than that currently depicted.


...Lower Colorado and Vicinity...

As detailed in the recently issued Day 2 Convective Outlook, the
enhancement of deep-layer shear and forcing for ascent will coincide
with an at least modestly unstable air mass late Saturday night into
early Sunday. That regime is likely to persist through at least
Sunday morning with an associated risk for a few severe storms
capable of severe wind gusts and perhaps a brief tornado or two. The
overall weakening of the midlevel trough by afternoon and limited
instability lead to uncertainty as to whether any severe weather
threat will spread north into the Great Basin and central Rockies.

..Mead.. 10/09/2026

Day 4-8 Convective Outlook  
NWS Storm Prediction Center Norman OK
0403 AM CDT Fri Oct 09 2026

Valid 121200Z - 171200Z

...DISCUSSION...
There is reasonably good agreement in 00Z deterministic and ensemble
guidance that a mid/upper-level low centered over the Sierra Nevada
or Great Basin on Day 4/Monday will evolve into an open wave while
progressing into the Great Plains on Day 6/Wednesday. Thereafter,
model spread increases in the evolution of the large-scale pattern.

...Day 4/Monday...

Some severe weather threat could materialize during the afternoon
along a surface boundary over the Upper Midwest where at least
modest instability will coincide with sufficiently strong deep-layer
shear to support organized storm modes. However, low-amplitude
ridging downstream from the western U.S. trough along with
uncertainty in the extent of air mass destabilization renders the
threat too questionable to include a 15% area.


...Day 5/Tuesday...

Increasing height falls and midlevel flow will overspread the
central and southern High Plains, which in turn will induce a
deepening lee cyclone, likely over southeast CO. At the surface, a
front is expected to stretch from the low through the OH Valley into
the Mid-Atlantic with a dryline trailing south from the cyclone into
eastern NM or western TX. Isolated strong to severe storms appear
possible along the length of the front from the Mid-Atlantic into
the central and southern Plains. Organized severe storm potential
appears most probable over the central and southern High Plains
Tuesday afternoon into evening in the vicinity of the lee cyclone
and strengthening low-level jet, where the strongest forcing for
ascent and vertical shear will coincide.


...Day 6/Wednesday...

As mentioned above, there is overall model agreement that a
short-wave trough and a strengthening deep-layer wind field will
advance into the Great Plains at this time. However, there are
slight timing and latitudinal differences in the track of the
midlevel system and the associated surface low. Despite these
differences, it does appear that a broad, moist, and unstable warm
sector will exist. As such, organized severe storms appear possible
with the highest confidence in occurrence over portions of eastern
KS into MO where guidance currently indicates the most favorable
overlap of instability and vertical shear. The currently delineated
area may move slightly and/or expand in the coming days as forecast
confidence increases.


...Days 7 and 8/Thursday and Friday...

Some severe weather threat could develop over the Great Lakes and OH
Valley on Thursday in association with the mid-level trough
discussed in the previous sections. However, confidence in organized
severe storm potential is currently too low given the model
variability in the specific details of the trough and associated
frontal system.

Day 1 Fire Weather Outlook  
NWS Storm Prediction Center Norman OK
0211 AM CDT Fri Oct 09 2026

Valid 091200Z - 101200Z

...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF NORTHEAST WYOMING...

...Synopsis...
An upper-level trough will dig southeastward into the Pacific
Northwest today as a deepening surface low progresses eastward
across southern Canada and an attendant cold front advances
southeastward across the Northwest and Northern Rockies. This will
occur in the wake of persistent upper-level ridging and prolonged
dry, warm conditions that have significantly cured fuels across
portions of the region. This combination of meteorological
conditions and receptive fuels (ERCs forecast to commonly exceed the
80th percentile) will create impactful fire weather conditions
across parts of the northern/western CONUS today.

...Much of Wyoming, central Montana, southwestern South Dakota, and
far northwest Nebraska...
A combination of the deepening surface low across southern Canada,
the approaching surface cold front, and lee troughing across the
High Plains will foster a tightening surface pressure gradient
across portions of the northern Plains today. The resultant enhanced
west-southwesterly flow (with widespread sustained winds of 15-25
mph) will drive well above-normal temperatures and promote
seasonally deep boundary-layer mixing that will support RH
reductions to 10-20%. With ERCs commonly at or above the 80th
percentile, this will support a broad region of elevated fire
weather concerns from northern/central Montana southward into much
of Wyoming, southwestern South Dakota, and portions of the Nebraska
Panhandle. Furthermore, critical fire weather concerns are forecast
to develop across portions of northeastern Wyoming, where the most
favorable overlap of 20+ mph winds and RH around 15% is expected.

While stronger sustained winds (20-25 mph) are also forecast in the
lee of the Northern Rockies across portions of central Montana, the
passage of the cold front around 00 UTC (6 PM MDT) is expected to
bring increasing moisture, a shift to weakening northwesterly winds,
and chances for precipitation.

...Southeast Oregon, Northeast California, and the far western Great
Basin...
West-southwesterly flow will similarly support warm temperatures and
seasonally deep mixing from southeastern Oregon into northeastern
California, northern Nevada, and southwestern Idaho. A tightening
surface pressure gradient ahead of the approaching cold front will
allow surface winds to strengthen to 15-20 mph amid minimum RH
values of 15-20%. These meteorological conditions will overlap with
receptive fuels to support an elevated fire weather threat. Winds
will then shift to north-northwesterly and gradually weaken as the
cold front passes through the region after 00 UTC (5 PM PDT).

..Chalmers.. 10/09/2026

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