Day 1 Convective Outlook RESENT 2
NWS Storm Prediction Center Norman OK
1155 AM CDT Thu Oct 15 2026

Valid 151630Z - 161200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE
MIDWEST...

...SUMMARY...
Thunderstorms capable of severe wind gusts and a tornado or two are
possible today across parts of the middle Mississippi and Ohio
Valleys.

...Midwest/Ohio Valley...
Extreme/record-caliber seasonal moisture content exists over the
region with warm-sector prevalent 2+ inch Precipitable Water values
and surface dewpoints in excess of 70F. A surface wave over the
middle part of Missouri late this morning should gradually/modestly
deepen as it progresses east-northeastward near a northward-shifting
warm front, although the front/warm sector are a bit muddled by
ongoing convection across southern portions of Missouri and
Illinois. 

Current split flow over the Great Plains will quickly resolve, with
a central Plains shortwave trough/speed max phasing with a
broader-scale upper trough over the Upper Midwest through tonight.
The net result will be a strengthening of deep-layer winds
along/north of the warm sector that will shift poleward, although to
what exact degree/spatial extent is uncertain given some of the
ongoing convection.

At least some scattering of warm-sector cloud cover, diurnal heating
and the increasing moisture content with northward extent will allow
for modest cool season destabilization, with SBCAPE potentially
exceeding 1000 J/kg across the lower Wabash Valley and
southern/downstate portions of Illinois and Indiana. This should
allow for re-development/intensification of storms this afternoon,
although the exact magnitude of today's severe risk is still a bit
uncertain and contingent on surface heating/destabilization. But
this scenario could include a few supercells, with the possibility
of a semi-focused severe/some tornado risk near the warm front,
which may be augmented by some of the prior convection, and ahead of
the surface low. Supercells aside, some semi-organized clusters
capable of wind damage should evolve within the high-moisture
content environment and 40+ kt effective shear. Overall storm
intensity is likely to wane within a couple hours of sunset,
generally by late evening.

...North/West Texas...
An outflow-augmented cold front will continue to spread
southeastward. The tendency for post-frontal convection should
remain the dominant scenario with boundary-parallel deep-layer flow
contributing to a more anafrontal character. Gradual diurnal heating
could support some intensification of storms along the leading edge
of the composite boundary this afternoon. As such, some stronger
wind gusts are plausible, but this scenario and related potential
for organized severe storms is currently expected to remain limited.

..Guyer/Marsh.. 10/15/2026

Day 2 Convective Outlook  
NWS Storm Prediction Center Norman OK
1225 PM CDT Thu Oct 15 2026

Valid 161200Z - 171200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF
THE MID ATLANTIC INTO SOUTHERN NEW ENGLAND...

...SUMMARY...
Scattered damaging gusts and perhaps a brief tornado may accompany a
squall line that is expected across the Mid-Atlantic into New
England tomorrow (Friday).

...Synopsis...
A pronounced, positively tilted upper trough will continue to
amplify as it rapidly approaches the East Coast tomorrow (Friday).
Accompanying this upper trough will be a strong surface cyclone,
which will track from the eastern Great Lakes to northern New
England during the day. A marginally unstable airmass will advect
ahead of a surface trough attendant from the cyclone, supporting
deep-moist convective potential amid an environment characterized by
strong forcing and vertical wind shear. As such, severe storms will
be possible across portions of the Mid-Atlantic into southern New
England late tomorrow morning into the evening hours.

...Mid-Atlantic into southern New England...
As the upper trough amplifies and the surface cyclone deepens over
the northern Appalachians, low-level convergence along the attendant
surface trough will increase into the morning hours, resulting in
the development of low-topped convection that will quickly evolve
into a squall line across western NY/PA. The northward advection of
mid 60s F surface dewpoints beneath 6 C/km mid-level lapse rates
will result in 500 J/kg MLCAPE on a widespread basis ahead of the
line, with locally higher values approaching 1000 J/kg in spots.
Some guidance members suggest that surface airmass recovery may be
brief ahead of the squall line given the potential for widespread
antecedent cloud cover. Still, strong tropospheric wind fields will
accompany the squall line, with forecast soundings showing 50+ kt
flow as low as 800-700 mb, with 35-40 kt flow contained within the
boundary layer, just above the surface.  

Regardless of the degree of destabilization that precedes the squall
line, downward momentum transport of the stronger flow aloft within
the squall line should support strong to occasionally severe surface
gusts, mostly in the 35-55 kt range. Scattered instances of
tree/wire damage are expected, starting from around western PA
during the late morning hours, to the East Coast around early
evening.

..Squitieri.. 10/15/2026

Day 1 Fire Weather Outlook  
NWS Storm Prediction Center Norman OK
1132 AM CDT Thu Oct 15 2026

Valid 151700Z - 161200Z

...CRITICAL FIRE WEATHER AREA FOR WESTERN L.A. COUNTY AND
SOUTHEASTERN VENTURA COUNTY...

...17Z Update...
...Southern California...
The forecast remains on track as critical fire weather conditions
continue through the late morning hours across western L.A. county
and southeastern Ventura county as a dry, offshore flow pattern
persists over the region. East-northeast winds of 10-20 mph have
been observed in Simi Valley and adjacent mountain ranges with
current surface observations showing sustained east-northeast winds
of 25-35 mph with gusts of 45-55 mph in favored terrain gap areas
and exposed ridgetops. Winds will briefly diminish this afternoon
before ramping up again tonight into D2/Friday morning. Current RH
in the 15-20% range will fall to as low as 10% in some valleys this
afternoon. An elevated fire weather threat surrounds the corridor of
stronger winds across southern CA.

...Sierra Nevada, portions of the Sacramento Valley and Napa
Valley...
Farther north, the broader offshore pattern will impact the western
slopes of the Sierra Nevada today. Downslope east-northeast winds of
10-15 mph (locally 20 mph) along with RH as low as 15% this
afternoon are expected after poor RH recoveries below 30% this
morning in some locations. Similarly dry, northerly to northeasterly
flow will affect portions of the Sacramento Valley and Napa Valley
through this afternoon as RH falls to around 10% this afternoon in
lower elevations.

..Williams.. 10/15/2026

.PREV DISCUSSION... /ISSUED 0107 AM CDT Thu Oct 15 2026/

...Synopsis...
A mid-level low over the central Plains will weaken and transition
to an open wave, quickly becoming absorbed within defined troughing
over the Upper Midwest. Meanwhile, a cutoff low will detach into the
Desert Southwest as surface high pressure migrates into the
Intermountain West and central CONUS. As a result, an increasing
offshore pressure gradient will promote a fire weather threat for
portions of southern CA that have not seen recent rainfall. 

...Southern California...
The fire weather threat will increase markedly early this morning
into the early afternoon hours as offshore flow accelerates across
portions of southern CA. Resultant east-northeast winds of 15-25 mph
will emerge with related downslope drying from a dry airmass
originating from the Colorado Plateau, allowing for RH reductions as
low as 10%. A corridor of stronger east-northeast winds of 20-30 mph
with gusts of 40-50 mph coupled with low RH will support critical
fire weather conditions in the Simi Valley area of western L.A.
county and southeastern Ventura county.

...Sierra Nevada, portions of the Sacramento Valley and Napa
Valley...
Increasing easterly downslope flow and drying into the Sacramento
Valley will promote elevated fire weather conditions for the Sierra
Nevada foothills this afternoon. Poor overnight RH recoveries with
some locations not exceeding 30% will precondition fuels where ERCs
are at the 80-90th percentiles. East winds of 10-15 mph (locally
20-25 mph in favored valley corridors) and daytime RH of 15% will
support an Elevated fire weather threat.

A building ridge aloft supporting above normal temperatures and very
dry conditions along with offshore flow trajectories will bring a
fire weather threat to portions the Sacramento Valley and adjacent
Napa Valley area. North winds of around 15 mph in the Sacramento
Valley will transition to east-northeast over Napa Valley and nearby
coastal ranges as RH falls to as low as 10% by this afternoon.

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