SPC AC 190600
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0100 AM CDT Sun Jul 19 2026
Valid 191200Z - 201200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM NORTH GEORGIA
INTO SOUTHERN VIRGINIA AND ACROSS THE DAKOTAS INTO WESTERN
MINNESOTA...
...SUMMARY...
Severe thunderstorms capable of damaging winds will be possible from
parts of north Georgia, across the Carolinas, and into southern
Virginia this afternoon. Additional severe thunderstorms capable of
damaging winds and large hail will be possible this afternoon and
evening across parts of the Dakotas and western Minnesota.
... Synopsis ...
The base-state mid-level pattern today will feature a western US
ridge and eastern US trough, with a weak closed low over the
northeast Gulf. Within this background flow field, a short-wave
trough will be exiting the Northeast US and a closed low across the
Canadian Prairies will crest the western ridge before digging
southeast late in the day toward the Upper Midwest.
At the surface, a large anticyclone will settle into the Great Lakes
region during the day. On the periphery of this anticyclone, a cold
front will be draped from coastal Virginia to the west-southwest,
before arcing northwest into the Mid-Mississippi Valley and then
into the Upper Midwest. This front will sag south across the eastern
US, while beginning to lift north and east across the Mississippi
Valley and Upper-Midwest. The front will act to delineate a very
warm/hot and moist airmass to the south and west from a cooler/dryer
airmass to the north and east.
... Georgia into southern Virginia and the greater Southeast ...
To the south of the advancing surface front, temperatures will warm
into the low-to-mid-90Fs from northern Georgia into southern
Virginia. At the same time, surface dewpoints of the upper-60Fs and
low-70Fs will be maintained. The result will be an strongly unstable
environment with HREF ensemble mean MUCAPE between 1500-2000 J/kg
across the region. Forecast soundings show precipitable water
greater than 1.75 inches across much of the area, with a band of
precipitable water in excess of 2 inches. This, coupled with steep
sub-cloud layer lapse rates (approaching 8 C/km) which will support
wind damage potential with any sustained thunderstorm updraft.
Surrounding this area, more scattered thunderstorm development is
expected within the moist and unstable environment. At this time, it
appears a corridor of higher likelihood for thunderstorm development
will extend from southeast Louisiana northeast toward northern
Georgia. This increased thunderstorm activity appears to be
associated with a band of modest convergence in the 850-700 millibar
layer to the north of a weak low across the northeast Gulf. Damaging
wind gusts will be possible with some of these storms.
Another potential area of damaging wind gusts will be across
north-central Florida into far south-central Georgia. Here, HREF
guidance shows an east-northeast expanding band of thunderstorms
emanating from the low over the northeast Gulf.
... Dakotas into western Montana ...
Temperatures are expected to warm into the upper-90Fs to the
low-100Fs during the afternoon to the east of a low-level trough
axis developing in the lee of the Rockies in the northern High
Plains. To the east of this trough axis, HREF ensemble mean
dewpoints in the mid-to-upper-60Fs will combine with those hot
afternoon temperatures to support a very unstable environment, with
HREF ensemble mean MUCAPE values between 1500-2000 J/kg across the
Dakotas and individual members considerably higher (3000-4000 J/kg).
Scattered thunderstorms are expected to develop across the Dakotas
by mid afternoon as convective temperatures are approached and
modest height falls overspread the area. Long, straight hodographs
and effective-layer shear around 40-knots will support supercellular
structures, including storm splits, early in the thunderstorm
convective life cycle. Large hail, potentially in excess of 2
inches, will be possible with these initial storms. However, dry
sub-cloud layers and low-level lapse rates around 9 C/km will
support strong convective outflows that will tend to favor upscale
growth, especially in regions where storm splits interact with one
another. One or more convective clusters will move east-southeast
during the late afternoon and evening continuing the threat for
damaging winds, before eventually weakening overnight.
..Marsh/Weinman.. 07/19/2026
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1300Z
SPC AC 190534
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1234 AM CDT Sun Jul 19 2026
Valid 201200Z - 211200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS FAR
SOUTHEAST MN...NORTHEAST IA...NORTHERN IL...WI...AND THE UPPER
PENINSULA OF MICHIGAN...
...SUMMARY...
Severe thunderstorms are probable across portions of the Upper
Midwest and Great Lakes vicinity on Monday. Swaths of damaging winds
will be the most likely hazard, with isolated large hail as well.
Isolated strong to damaging gusts may occur over parts of the
Carolinas.
...Upper Midwest/Great Lakes...
An upper shortwave trough initially over the northern Plains early
Monday will strengthen as it progresses east/southeast over the
Upper Midwest/Great Lakes. As this occurs, mid/upper
west/northwesterly flow will intensify, with most guidance showing
50-60 kt at 500 mb, and 850-700 mb potentially increasing to 40+ kt.
At the surface, low pressure will deepen as it shifts east across
Ontario and the northern Great Lakes. A trailing cold front will
sweep east/southeast during the afternoon and evening, becoming
positioned from northern Lower MI to northern MO by Tuesday morning.
Ahead of the front, a very moist airmass characterized by 70s
dewpoints will be in place. This moisture will modestly decrease
east of Lake MI. Within the moist axis, strong to extreme
instability is forecast (particularly from IA into WI).
Some uncertainty remains concerning placement and extent of
potential ongoing convection early Monday, and will depend on
evolution of storms overnight in the Day 1/Sunday period, and the
timing of a possible lead shortwave impulse. Morning convection
could have implications for where corridors of greater severe
potential will develop during the afternoon/evening. Nevertheless,
the region will experience strong warm advection ahead of the cold
front, and airmass recovery is likely.
Supercell wind profiles are evident in forecast soundings. A
favorable thermodynamic/kinematic environment could support initial
supercells capable of all severe hazards, and possibly significant
severe. However, given the progressive nature of the upper trough
and surface cold front, along with intensifying 850 mb flow by late
afternoon/evening, upscale growth into one or more bowing MCSs
appears possible. Significant damaging wind potential will increase
with a transition to linear storm mode. The south and east extent of
severe potential is also uncertain, but if a mature MCS develops
during the evening, it seems reasonable the severe wind risk could
persist into portions of Lower MI, northern IN and northwest OH
overnight.
...North Carolina vicinity...
Weak northwest flow aloft will persist across the Mid-Atlantic on
Monday. Modest lee troughing across the Piedmont will allow a
surface front to lift north across part of NC into VA, and spreading
rich boundary layer moisture across the region. Strong heating will
result in moderate destabilization and scattered thunderstorms will
develop during the afternoon. Deep-layer flow will remain modest,
but sufficient clustering, high PW values, and steep low-level lapse
rates will support isolated damaging wind potential.
..Leitman.. 07/19/2026
WUUS02 PTSDY2
SPC AC 190710
Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0210 AM CDT Sun Jul 19 2026
Valid 211200Z - 221200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS THE OHIO
VALLEY...
...SUMMARY...
Numerous severe thunderstorms are expected across a broad region
from the Ohio Valley into the Mid-Atlantic and Northeast on Tuesday.
All severe hazards are possible, but swaths of damaging wind gusts
should be the primary severe risk Tuesday afternoon into the
nighttime hours.
...Ohio Valley to the Mid-Atlantic/Northeast...
A vigorous upper trough will spread across the region on Tuesday. A
broad area of strong deep-layer flow, especially by July standards,
will overlap a very moist airmass ahead of an eastward progressing
surface cold front. Widespread dewpoints in the upper 60s to low 70s
are expected. While some uncertainty exists regarding potential
morning convection in the form of a remnant MCS from the Day
2/Monday period across parts of MI/IN/OH, pockets of stronger
heating should occur, and given rich moisture/continuous warm
advection ahead of the surface front, strong destabilization is
forecast. While boundary layer moisture will begin the day somewhat
muted across parts of the Northeast, strong warm advection and
increasing southerly low-level flow across the Mid-Atlantic into the
Northeast will also result in northward transport of richer boundary
layer moisture through evening. While instability may be somewhat
less further east into the Mid-Atlantic/Northeast, strong deep-layer
flow will envelop this region as well.
Supercell wind profiles are evident across the broad warm sector,
with 40+ kt westerly flow common above 850 mb. Where supercells can
develop and be maintained, all severe hazards will be possible.
However, given the strong flow field, and the progressive trough and
surface front, one or more bowing segments will quickly develop and
spread eastward. Swaths of damaging winds will be the primary
concern during the afternoon and into the nighttime hours.
..Leitman.. 07/19/2026
WUUS03 PTSDY3
NOTE: THE NEXT DAY 3 OUTLOOK IS SCHEDULED BY 1930Z
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