SPC 0730Z Day 3 Outlook

Day 3 Convective Outlook  
NWS Storm Prediction Center Norman OK
0230 AM CDT Fri Oct 17 2025

Valid 191200Z - 201200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS
OF THE OHIO VALLEY AND APPALACHIANS...

...SUMMARY...
Severe storms with a threat mainly for damaging winds are possible
over parts of the Ohio Valley and Appalachians Sunday.

...Synopsis...
A strong neutral to slightly negative tilt upper trough over the OH
Valley and Great Lakes is forecast to continue intensifying as it
moves quickly eastward Sunday. At the base of the trough, a 90+ kt
jet streak will lift northward into the upper OH Valley and
Northeast deepening a surface low over the Great Lakes and eastern
Canada. Strong southerly winds ahead of the low will support a
modestly moist air mass from eastern OH/KY into western PA and WV. A
cold front expected to move eastward with the low will serve as a
focus for thunderstorm potential Sunday morning through Sunday
evening.

...OH Valley and Appalachians...
A squall line is likely to be ongoing at the start of the period
from central/eastern OH into northern KY ahead of the front and
deepening surface low. Strong ascent from the trough/jet streak
should maintain this shallow convective line into portions of PA/WV
by early afternoon. With upper 50s to low 60s F dewpoints and only
modest heating, buoyancy appears limited. However, the strong flow
aloft should still support a risk for damaging gusts. Backed flow
ahead of the surface low will favor large low-level shear which
could support embedded rotation with the potential for a brief
tornado or two. Storms will gradually weaken with eastward extent as
available buoyancy wanes into the evening.

...Central Gulf Coast and the Southeast...
At the start of the period, a few storms may be ongoing along the
front as it continues east/southeastward across southern MS/AL and
western FL. With marginal buoyancy and on the southern fringes of
the stronger flow aloft, a few strong wind gusts cannot be ruled
out, but convection should weaken through the morning before moving
offshore.

The cold front will continues eastward through the remainder of the
day with remnant showers and cloud cover likely ahead of it. Still,
some heating and destabilization is possible across the Southeast
and southern Appalachians. However, weak subsidence is expected over
much of the region as the primary upper trough and jet streak begin
to lift away to the north. This currently suggests limited
redevelopment will occur along the front Sunday afternoon, though
there remains substantial uncertainty. While isolated storms cannot
be ruled out, confidence remains too low for severe probabilities.

..Lyons.. 10/17/2025

No watches are valid as of Fri Oct 17 07:34:01 UTC 2025.

No Mesoscale Discussions are in effect as of Fri Oct 17 07:34:01 UTC 2025.

SPC Day 2 Fire Weather Outlook

Day 2 Fire Weather Outlook  
NWS Storm Prediction Center Norman OK
0148 AM CDT Fri Oct 17 2025

Valid 181200Z - 191200Z

...Synopsis...
A surface low will deepen across the central/southern Plains on
D2/Saturday as a front shifts south across the southern Plains. The
dryline will be located across the Texas Panhandle into western
Oklahoma. Behind the dryline, relative humidity reductions to 15-20
percent will overlap with warm and breezy conditions ahead of the
southward moving cold front. Overall, ensemble guidance keeps
spatial extent of any Critical conditions very limited. As such, an
Elevated area was maintained with this outlook though some localized
Critical conditions will be possible.

..Thornton.. 10/17/2025

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

SPC Day 1 Fire Weather Outlook

Day 1 Fire Weather Outlook  
NWS Storm Prediction Center Norman OK
0147 AM CDT Fri Oct 17 2025

Valid 171200Z - 181200Z

...NO CRITICAL AREAS...

...Synopsis...
Fire weather concerns will remain low today across the CONUS. A
large scale trough will gradually shift into the Plains through
D2/Saturday with post-frontal west and northwesterly breezes
expected in the central/high Plains. Cooler temperatures and higher
relative humidity should mitigate fire weather concerns in this
region. 

High pressure will build back in across the western US with increase
in onshore flow and breezy/dry conditions in wind prone areas near
the high terrain in southern California. Recent rainfall in this
region should help mitigate the fire weather risk.

..Thornton.. 10/17/2025

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

SPC 0600Z Day 2 Outlook

Day 2 Convective Outlook  
NWS Storm Prediction Center Norman OK
0100 AM CDT Fri Oct 17 2025

Valid 181200Z - 191200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE ARKLATEX
TO THE CENTRAL MISSISSIPPI AND LOWER OHIO VALLEYS...

...SUMMARY...
Scattered severe thunderstorms are possible Saturday across parts of
the Ark-La-Tex, Ozarks, mid Mississippi and lower Ohio Valleys.
Damaging winds, a few tornadoes and hail are possible.

...Synopsis...
A broad upper trough over the central US is forecast to deepen
throughout Saturday as several peripheral shortwave features
coalesce over the central MS Valley. The most prominent of these
features will start the period over the southern Rockies before
phasing with the broader trough across the southern Plains Saturday
night. A powerful 100+ kt mid-level jet exiting the central
Rockies/High Plains will round the base of the consolidated trough
helping to rapidly deepen a surface low over the OH Valley and Lower
Great Lakes. A cold front with strong southerly flow ahead of it
will sweep eastward from the OH/MS Valleys into the Mid South
overnight supporting scattered to numerous thunderstorms.

...Ohio Valley to the Ozarks...
Mid-level ascent with an embedded perturbation will expand over the
slow-moving cold front initially positioned from the Ozarks to the
Lower Great Lakes and OH Valley early Saturday. Southerly flow will
allow for substantial moistening as low to mid 60s F surface
dewpoints move northward across MO/IL, into western KY and OH and
eventually Lower MI. Continued low-level warm advection should
result in scattered to numerous thunderstorms along the front by mid
afternoon into the evening. While buoyancy should be limited
(500-1000 J/kg) owing to increasing storm coverage and cloud cover,
elongated mid/upper-level hodographs with largely unidirectional
shear will favor some potential for organized short line segments.
This activity should generally become more organized into the
afternoon/evening as the cold front strengthens and surges eastward
as the upper trough and surface low organize. This will support a
risk for damaging gusts and perhaps a couple embedded tornadoes
should a more coherent QLCS develop and persist overnight.

...Southern Plains to the Mid MS Valley...
Ahead of the primary southern stream shortwave trough, rich
low-level moisture will advect northward across parts of TX/OK into
the central and lower MS Valley. While some potential exists for
early morning convection to modulate the environment, current
guidance suggests diurnal destabilization (MLCAPE ~ 2000 J/kg) is
likely ahead of surface trough trailing the developing low farther
north. Scattered thunderstorm development is expected in the
afternoon from northern AR into eastern OK and North TX with the
potential for supercell structures capable of damaging gusts and
hail initially.

With time, the surface cold front over the southern Plains should
begin to surge eastward as the advancing shortwave trough phases
with the strengthening upper trough. Vertical shear will increase
substantially as the mid-level jet streak noses into the Mid South
fostering strong low-level mass response. The cold front will likely
outpace and overtake the surface trough and ongoing convection
supporting rapid upscale growth into a squall line across the
central MS Valley Saturday evening into the early overnight hours.
While uncertainty about the degree of instability given the
overnight timing remains, strengthening low-level wind fields and
mid 60s F dewpoints may delay boundary-layer decoupling long enough
to support a damaging wind and embedded tornado threat overnight as
the QLCS moves eastward.

..Lyons.. 10/17/2025

SPC 1200Z Day 1 Outlook

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
1220 AM CDT Fri Oct 17 2025

Valid 171200Z - 181200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM PARTS OF OK
INTO CENTRAL/EASTERN KS AND WESTERN MO...

...SUMMARY...
Thunderstorms with isolated hail and strong to severe wind gusts
will be possible this evening through the overnight period from the
southern and central Plains into the lower Missouri Valley.

...Synopsis...
A mid/upper-level cyclone initially near the ND/MB border will move
northeastward through the day, as a trailing positive-tilt trough
and attendant weak cold front move eastward across the Upper Midwest
into the central/southern Great Plains. A mid/upper-level shortwave
near the base of this trough is forecast to amplify by late in the
period across the southern Rockies. Farther northwest, an upstream
shortwave trough and vigorous mid/upper-level jet will dig
southeastward across the northern Rockies late tonight. 

...Parts of the southern/central Plains into the lower MO Valley...
Weak to locally moderate destabilization will be possible by late
afternoon from parts of the southern/central Plains into the lower
MO Valley, along/ahead of the weak surface trough/front. Generally
weak midlevel lapse rates and modest large-scale ascent will tend to
limit diurnal storm potential, but isolated strong-storm development
cannot be ruled out by early evening. An increase in primarily
elevated convection is expected from mid/late evening onward, in
response to a nocturnally strengthening low-level jet, and eventual
approach of the southern Rockies shortwave trough. 

Increasing deep-layer flow/shear and some steepening of midlevel
lapse rates late in the period will support potential for at least
transient storm organization tonight, though guidance continues to
vary regarding the coverage and intensity of overnight elevated
convection. Isolated large hail and localized strong/damaging gusts
will be possible with the strongest storms into early Saturday
morning.

..Dean/Thornton.. 10/17/2025