690 
ACUS01 KWNS 160527
SWODY1
SPC AC 160526

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
1226 AM CDT Mon Mar 16 2026

Valid 161200Z - 171200Z

...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON
ACROSS PARTS OF CENTRAL MARYLAND...MUCH OF CENTRAL AND EASTERN
VIRGINIA...CENTRAL NORTH CAROLINA AND ADJACENT PORTIONS OF SOUTH
CAROLINA...

...SUMMARY...
Fast moving thunderstorms may become widespread and accompanied by
the risk for damaging wind gusts and a few tornadoes across the Mid
Atlantic today.  There is potential that a couple of storms could
become capable of producing strong and long track tornadoes.

...Discussion...
Models indicate that large-scale mid-level ridging will maintain
amplitude across the Pacific coast through the Canadian Prairies and
U.S. Rockies into early Tuesday and beyond.  At the same time, it
appears that downstream ridging will undergo further amplification
just east of the Atlantic Seaboard, with only very slow eastward
progression of large-scale troughing in between, across the
Mississippi Valley into the Atlantic Seaboard.

It does appear that one significant short wave perturbation will
gradually pivot through the base of the troughing, toward the
Cumberland Plateau during the day today, before rapidly accelerating
northward near the Appalachians toward southwestern Quebec this
evening through the overnight hours.  Models suggest that this will
eventually provide support for a rapidly deepening secondary surface
cyclone across Quebec, downstream of an occluding and weakening
cyclone across the lower Great Lakes vicinity.

Surface troughing ahead of the trailing cold front is also forecast
to undergo notable deepening to the east of the Allegheny Front and
Blue Ridge  today, and it appears that a rather sharp surface
pressure fall/rise couplet will develop and overspread the northern
Mid Atlantic coast late this afternoon and evening with the passage
of the trough and trailing cold front.  The cold front may clear all
the Atlantic Seaboard, but perhaps portions of southern Florida and
the Keys, by 12Z Tuesday.

...Atlantic Seaboard...
Low-level moisture return is underway across the southern into
middle Atlantic Seaboard.  By early this afternoon, it appears that
60+ F surface dew points will advect as far north as the higher
terrain of central through northeastern Pennsylvania, with dew
points perhaps as high as the lower/mid 60s F across eastern North
Carolina and Virginia.  In advance of a pre-frontal squall line,
which may be ongoing and beginning to spread to the lee of the
southern Appalachians through the eastern Gulf Coast states at the
outset of the period, it appears that destabilization and
large-scale ascent may support scattered new thunderstorm
development fairly early in the day.  The extent to which this may
impact further destabilization through late afternoon remains
unclear.

Destabilization may also be impacted by relatively warm air/weak
lapse rates in mid/upper-levels, as models suggest that cold air
aloft will tend to lag to the west of the surface cold front.  Even
so, forecast soundings suggest that, with breaks in the overcast, at
least weak boundary-layer CAPE on the order of 500-1000 J/kg is
possible in the warm sector across the Mid Atlantic.  

In the presence of very strong southwesterly deep-layer mean flow on
the order of 50-60+ kt and strong to extreme low-level shear,
including at least modest clockwise curvature, the environment
appears potentially conducive to the evolution fast moving
supercells with potential to produce strong tornadoes.  Barring much
interference from other storms, which remains uncertain at this
time, at least a couple of these could become long track, given the
storm motions.

Otherwise, trailing this activity, the lee surface trough/cold front
might become a focus for a developing line of storms capable of
promoting the downward transfer of momentum with potential to
produce widespread damaging wind gusts.

Farther south, it appears that the initial squall line may be
maintained or re-intensify, with a continuing risk for strong to
severe wind gusts and potential for tornadoes into and across the
southern Atlantic coast.

..Kerr/Thornton.. 03/16/2026

$$


File: /home/ldm/var/data/BY_SOURCE/KWNS/ACUS01/20260316T0527.txt



825 
ACUS01 KWNS 160045
SWODY1
SPC AC 160043

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
0743 PM CDT Sun Mar 15 2026

Valid 160100Z - 161200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE LOWER OHIO VALLEY INTO MID SOUTH AND EASTERN GULF COAST
STATES...

...SUMMARY...
A squall line may continue to pose a risk for widespread strong to
severe wind gusts and perhaps a couple of tornadoes through late
evening as it progresses east of the middle Mississippi Valley into
the Ohio Valley.  The severe threat may continue into and through
the overnight hours as it advances east of the lower Mississippi
Valley toward the eastern Gulf Coast states.

...01Z Update...
The northern flank of the ongoing squall line, and closely trailing
cold front, just south of the center of the deep cyclone migrating
toward Lower Michigan, is beginning to undercut a narrow pre-frontal
plume of mid 50s F surface dew points advecting north-northeastward
through the lower Ohio Valley.  As this continues through the next
few hours, it appears that inflow may become characterized by
steadily decreasing CAPE, emanating from downstream a boundary layer
with dew points still in the upper 40s F from Lexington and
Louisville KY northward.  While this is likely to result in
weakening thunderstorm activity, it is possible that widespread
gusts generally approaching to exceeding 50 kt may be a bit slower
to diminish.

Farther south, although an initial plume of better pre-frontal
moisture return into the Mid South (characterized by lower 60s F dew
points) may be overtaken by the squall line shortly, another plume
of better boundary-layer moistening appears underway across eastern
Mississippi and western Alabama.  As this continues to develop
northward this evening, beneath 40 kt southerly 850 mb flow,
unstable inflow and strong shear may maintain or support
re-intensification of storms across the Tennessee Valley into
central and eastern Gulf States.  Although model output has been
varied, there remains at least some signal in potential for more
discrete downstream supercell development within strengthening
low-level warm advection late tonight across southeastern Alabama
and adjacent portions of the Gulf Coast states.  If this occurs,
forecast low-level hodographs could support a strong tornado or two.

..Kerr.. 03/16/2026

$$


File: /home/ldm/var/data/BY_SOURCE/KWNS/ACUS01/20260316T0045.txt



044 
ACUS01 KWNS 151959
SWODY1
SPC AC 151957

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
0257 PM CDT Sun Mar 15 2026

Valid 152000Z - 161200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON
INTO TONIGHT ACROSS MUCH OF THE LOWER/MID-MISSISSIPPI VALLEY...LOWER
OHIO VALLEY...TENNESSEE VALLEY...AND SOUTHEAST...

...SUMMARY...
Numerous to widespread severe/damaging winds and embedded tornadoes
will accompany an intense squall line across much of the lower/mid
Mississippi Valley this afternoon and evening. A couple of strong
tornadoes are also possible within and just ahead of this line
across parts of the lower Ohio Valley into the Mid-South and Gulf
Coast regions. The severe wind and tornado threat will likely
persist through tonight across portions of the Ohio
Valley/Southeast.

...20Z Update...
Some trimming to severe/thunder probabilities was done across
Missouri given the progression of the sharp cold front. Lapse rate
and shear profiles will favor supercells from near the Sabine Valley
into the Mississippi Delta region. There, hail to around 2 inches is
conditionally possible. The greatest potential for strong tornadoes
still appears to be within the mid-Mississippi Valley. Tornado
probabilities were adjusted based on the latest guidance. Lastly,
higher wind probabilities (45%) were expanded southeastward where
there is an increased signal in guidance for a coherent line of
convection to maintain intensity this evening/overnight. See the
previous discussion for additional details.

..Wendt.. 03/15/2026

.PREV DISCUSSION... /ISSUED 1130 AM CDT Sun Mar 15 2026/

...Lower Mississippi Valley/Southeast into the Ohio
Valley/Midwest...
Pronounced upper troughing over the northern/central Plains late
this morning will further amplify through the period as it ejects
east-northeastward across much of the MS Valley/Midwest. A 992 mb
surface low over northern MO will likewise develop northeastward
across the Midwest through the day, reaching northeast IL/northwest
IN by this evening and northern Lower MI by the end of the period.
Primary low-level jet will focus northward across the OH
Valley/Midwest this afternoon and evening, with a trailing/southern
portion present across parts of the Mid-South and lower MS Valley.
Associated strong low-level warm/moist advection will continue to
occur ahead of a sharp surface cold front that is expected to sweep
quickly east-southeastward through tonight over much of the
lower/mid MS Valley, OH/TN Valleys, and Southeast.

Low-level moisture remains fairly shallow/limited ahead of the cold
front per latest surface observations and area 12Z observed
soundings (ILX, SGF, JAN, LIX). Still, generally 50s surface
dewpoints should be present in a narrow warm sector across the OH
Valley/Midwest by late afternoon/early evening, with somewhat
greater moisture (upper 50s to low 60s surface dewpoints) southward
into the lower/mid MS Valley. Large-scale ascent attendant to the
approaching upper trough will aid in the erosion of a substantial
cap noted along/ahead of the cold front by early afternoon (18-20Z).
With even modest/filtered daytime heating, at least weak instability
should develop in a narrow corridor ahead of the front. This gradual
destabilization will support the potential for rapid thunderstorm
development within the next few hours.

General consensus of latest guidance is that a QLCS will quickly
strengthen/consolidate through the mid to late afternoon into the
evening as it moves quickly eastward across AR/MO and the lower/mid
MS Valley and lower OH Valley. Deep-layer shear of 40-50+ kt
associated with a strengthening west-southwesterly mid-level jet
overspreading the warm sector will support organization with the
maturing QLCS. Given the expected strength of the flow in the
boundary layer (50-60+ kt), numerous to potentially widespread
severe/damaging winds up to 60-80 mph are expected wherever the QLCS
can remain surface based. Strong low-level shear will also be
present to foster embedded mesocirculations and the potential for
several QLCS tornadoes.

The opportunity for supercells to develop ahead of the squall line
remains uncertain, as residual low-level capping may inhibit open
warm sector development. Still, greater instability should be
present from the western KY/TN vicinity southward into the lower MS
Valley. Any supercells that can form ahead of the line across these
areas and/or remain at least semi-discrete within the line could
produce strong (EF-2+) tornadoes, as low-level shear and related
elongated/curved hodographs will be quite favorable for updraft
rotation. Although boundary-layer instability will become
increasingly weak with northward extent into the OH Valley tonight,
a continued threat for numerous severe/damaging winds will likely
continue with the QLCS as it shifts eastward across the OH/TN
Valleys and much of the Southeast this evening through early Monday
morning. Have therefore expanded/combined the wind-driven Enhanced
Risk areas in southern/central MS/AL into western GA and eastern TN.
Some chance for pre-frontal supercells and strong tornado potential
ahead of the QLCS may also exist late tonight across portions of
southeast AL, the FL Panhandle, and southwest GA.

...Florida Peninsula into the Carolinas...
Low-level moisture will gradually spread northward through tonight
from the FL Peninsula to the southern Appalachians and into parts of
the Carolinas, well ahead of the amplifying upper trough over the MS
Valley. While forcing will remain generally weak/nebulous, there is
some chance for isolated hail/damaging winds with thunderstorms this
afternoon across much of the FL Peninsula and the Keys. The severe
threat across coastal GA/SC/NC appears conditional on thunderstorms
spreading inland from the Gulf Stream tonight into early Monday
morning. However, an isolated threat for damaging winds and perhaps
a tornado would exist in a gradually improving environment if these
cells form and move inland. Have therefore maintained the Marginal
Risk across this region with no changes.

$$


File: /home/ldm/var/data/BY_SOURCE/KWNS/ACUS01/20260315T1959.txt



687 
ACUS01 KWNS 151632
SWODY1
SPC AC 151630

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
1130 AM CDT Sun Mar 15 2026

Valid 151630Z - 161200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON
AND TONIGHT ACROSS MUCH OF THE LOWER/MID MISSISSIPPI VALLEY...LOWER
OHIO VALLEY...TENNESSEE VALLEY...AND SOUTHEAST...

...SUMMARY...
Numerous to widespread severe/damaging winds and embedded tornadoes
will accompany an intense squall line across much of the lower/mid
Mississippi Valley this afternoon and evening. A couple of strong
tornadoes are also possible within and just ahead of this line
across parts of the lower Ohio Valley into the Mid-South and Gulf
Coast regions. The severe wind and tornado threat will likely
persist through tonight across portions of the Ohio
Valley/Southeast.

...Lower Mississippi Valley/Southeast into the Ohio
Valley/Midwest...
Pronounced upper troughing over the northern/central Plains late
this morning will further amplify through the period as it ejects
east-northeastward across much of the MS Valley/Midwest. A 992 mb
surface low over northern MO will likewise develop northeastward
across the Midwest through the day, reaching northeast IL/northwest
IN by this evening and northern Lower MI by the end of the period.
Primary low-level jet will focus northward across the OH
Valley/Midwest this afternoon and evening, with a trailing/southern
portion present across parts of the Mid-South and lower MS Valley.
Associated strong low-level warm/moist advection will continue to
occur ahead of a sharp surface cold front that is expected to sweep
quickly east-southeastward through tonight over much of the
lower/mid MS Valley, OH/TN Valleys, and Southeast.

Low-level moisture remains fairly shallow/limited ahead of the cold
front per latest surface observations and area 12Z observed
soundings (ILX, SGF, JAN, LIX). Still, generally 50s surface
dewpoints should be present in a narrow warm sector across the OH
Valley/Midwest by late afternoon/early evening, with somewhat
greater moisture (upper 50s to low 60s surface dewpoints) southward
into the lower/mid MS Valley. Large-scale ascent attendant to the
approaching upper trough will aid in the erosion of a substantial
cap noted along/ahead of the cold front by early afternoon (18-20Z).
With even modest/filtered daytime heating, at least weak instability
should develop in a narrow corridor ahead of the front. This gradual
destabilization will support the potential for rapid thunderstorm
development within the next few hours.

General consensus of latest guidance is that a QLCS will quickly
strengthen/consolidate through the mid to late afternoon into the
evening as it moves quickly eastward across AR/MO and the lower/mid
MS Valley and lower OH Valley. Deep-layer shear of 40-50+ kt
associated with a strengthening west-southwesterly mid-level jet
overspreading the warm sector will support organization with the
maturing QLCS. Given the expected strength of the flow in the
boundary layer (50-60+ kt), numerous to potentially widespread
severe/damaging winds up to 60-80 mph are expected wherever the QLCS
can remain surface based. Strong low-level shear will also be
present to foster embedded mesocirculations and the potential for
several QLCS tornadoes.

The opportunity for supercells to develop ahead of the squall line
remains uncertain, as residual low-level capping may inhibit open
warm sector development. Still, greater instability should be
present from the western KY/TN vicinity southward into the lower MS
Valley. Any supercells that can form ahead of the line across these
areas and/or remain at least semi-discrete within the line could
produce strong (EF-2+) tornadoes, as low-level shear and related
elongated/curved hodographs will be quite favorable for updraft
rotation. Although boundary-layer instability will become
increasingly weak with northward extent into the OH Valley tonight,
a continued threat for numerous severe/damaging winds will likely
continue with the QLCS as it shifts eastward across the OH/TN
Valleys and much of the Southeast this evening through early Monday
morning. Have therefore expanded/combined the wind-driven Enhanced
Risk areas in southern/central MS/AL into western GA and eastern TN.
Some chance for pre-frontal supercells and strong tornado potential
ahead of the QLCS may also exist late tonight across portions of
southeast AL, the FL Panhandle, and southwest GA.

...Florida Peninsula into the Carolinas...
Low-level moisture will gradually spread northward through tonight
from the FL Peninsula to the southern Appalachians and into parts of
the Carolinas, well ahead of the amplifying upper trough over the MS
Valley. While forcing will remain generally weak/nebulous, there is
some chance for isolated hail/damaging winds with thunderstorms this
afternoon across much of the FL Peninsula and the Keys. The severe
threat across coastal GA/SC/NC appears conditional on thunderstorms
spreading inland from the Gulf Stream tonight into early Monday
morning. However, an isolated threat for damaging winds and perhaps
a tornado would exist in a gradually improving environment if these
cells form and move inland. Have therefore maintained the Marginal
Risk across this region with no changes.

..Gleason/Lyons.. 03/15/2026

$$


File: /home/ldm/var/data/BY_SOURCE/KWNS/ACUS01/20260315T1632.txt



289 
ACUS01 KWNS 151235
SWODY1
SPC AC 151233

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
0733 AM CDT Sun Mar 15 2026

Valid 151300Z - 161200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON
THROUGH TONIGHT ACROSS PARTS OF THE MID SOUTH INTO LOWER OHIO VALLEY
AND ACROSS PARTS OF THE EASTERN GULF COAST STATES...

...SUMMARY...
Widespread strong to severe wind gusts may accompany a developing
squall line across and east of the mid/lower Mississippi Valley this
afternoon into this evening.  A couple of strong tornadoes are also
possible within and just ahead of this line across parts of the
lower Ohio Valley into Mid South and Gulf Coast regions.

...Mid Mississippi/Lower Ohio/Tennessee Valleys...
An active severe weather event is expected to occur this afternoon
through tonight over a large part of the east-central CONUS.  Water
vapor imagery confirms a powerful shortwave trough is amplifying
over the central Plains this morning, with a deep surface low
tracking from northern MO into Lower MI during this forecast period.
 Very strong southerly low-level winds (50-75 knots at 850mb) in the
warm sector will transport 50s surface dewpoints rapidly northward,
resulting in widespread marginal to moderate CAPE values from Lower
MI to the Gulf coast.  Current indications are that thunderstorms
will begin increasing in coverage and intensity around midday as a
strong cold front surges into the region.  The initial storms over
AR/MO will track into an environment quite favorable for supercell
structures and tornadoes - but the intense linear forcing along the
front, and weak capping ahead of the front may short-circuit
discrete cell formation and mesocyclone development.  Nevertheless,
a conditional risk of significant tornadoes will exist through at
least early evening.

There will be an increasing risk of widespread damaging winds and
occasional embedded tornadoes along the squall line/cold front as it
sweeps eastward into the OH and TN Valleys during the late afternoon
and evening.  Extremely strong winds just above the surface will
allow deep-convective elements to produce severe winds.  This threat
may persist much of the night, spreading as far east as eastern
KY/TN and much of GA by 16/12z.

Earlier model runs suggested the development of a more favorable
environment for supercells and tornadoes late tonight over parts of
AL/GA/FL.  More recent model solutions have backed off from that
scenario, but will keep the ENH for now and re-evaluate with 12z
model cycle.

..Hart/Weinman.. 03/15/2026

$$


File: /home/ldm/var/data/BY_SOURCE/KWNS/ACUS01/20260315T1235.txt