• DAY1SVR: Day 1 Convective Outlook

    From Mike Powell@618:250/6 to All on Fri May 1 08:44:10 2026
    ACUS01 KWNS 011233
    SWODY1
    SPC AC 011231

    Day 1 Convective Outlook
    NWS Storm Prediction Center Norman OK
    0731 AM CDT Fri May 01 2026

    Valid 011300Z - 021200Z

    ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM THE TEXAS
    HILL COUNTRY INTO THE UPPER TEXAS COAST...AND ACROSS THE CENTRAL
    GULF COAST INTO THE FLORIDA PANHANDLE...

    ...SUMMARY...
    Thunderstorms with isolated severe wind gusts and hail will be
    possible today across parts of south-central and southeast Texas,
    and this evening into tonight along the central Gulf Coast.

    ...Synopsis and Discussion...
    Early morning satellite imagery shows several shortwave troughs,
    including one within the southern stream over northern Mexico and
    another moving into Ohio Valley within the base of a large cyclone
    centered over the northern Ontario/Quebec border vicinity. Recent
    surface analysis places a weak front from Deep South Texas
    northeastward through the western Gulf and central Plaquemines
    Parish, continuing through the north-central Gulf and across
    northern Florida. Numerous showers and thunderstorms are currently
    ongoing north of the front and downstream of the northern Mexico
    shortwave from the Texas Hill County eastward to the Upper Texas Coast.

    Thermodynamic conditions across these region are expected to remain
    largely unchanged throughout much of the day, with modest elevated
    instability persisting amid the moist southwesterly mid-level flow.
    Some modest increase in the mid-level flow is anticipated as the
    shortwave trough continues eastward through TX and into the Lower
    Mississippi Valley. An attendant increase in large-scale ascent is
    expected as well. Resulting increase in the deep-layer shear could
    result in slightly more organized storm structures and greater
    overall storm intensity this afternoon despite numerous preceding
    showers and thunderstorms, and little change in the overall
    thermodynamics. Large hail and damaging gusts are the primary risks
    with the strongest storms.

    A surface low is expected to develop ahead of the shortwave trough
    over the western Gulf, before then tracking quickly northeastward as
    the shortwave continues eastward. This low will likely be just off
    the Deep South Texas Coast by 00Z Saturday, and off of southern
    Plaquemines Parish by 06Z. Elevated thunderstorms are expected
    across the Lower MS Valley amid a combination of warm-air advection
    and large-scale ascent ahead of the shortwave. The strongest storms
    may be capable of producing small hail. The surface low may also
    track far enough north for the warm sector to advect into the
    near-coastal regions of southeast Louisiana, far southern
    Mississippi, southern Alabama and the western/central Florida
    Panhandle. If this occurs, surface-based storms could develop,
    enhancing the potential for damaging gusts as well as introducing a low-probability tornado risk.

    ..Mosier/Dean.. 05/01/2026

    $$
    --- MultiMail/DOS
    * Origin: Project Scorpio TEST (618:250/6)
  • From Mike Powell@618:250/6 to All on Sun May 3 09:12:46 2026
    ACUS01 KWNS 030538
    SWODY1
    SPC AC 030536

    Day 1 Convective Outlook
    NWS Storm Prediction Center Norman OK
    1236 AM CDT Sun May 03 2026

    Valid 031200Z - 041200Z

    ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF NORTHERN/CENTRAL MISSOURI INTO CENTRAL ILLINOIS...

    ...SUMMARY...
    A few strong thunderstorms are possible across parts of
    northern/central Missouri and central Illinois on Sunday.

    ...Synopsis...
    A short-wave trough with a belt of enhanced northwesterly flow
    within the broader eastern US trough will overspread the Missouri
    Valley through this evening. A weak cold front will extend across
    portions of the central Plains into the Missouri Valley. This
    boundary will be the focus for potential isolated thunderstorm
    development as the short-wave moves in across the region by the evening.

    ...Northern/central Missouri into central Illinois...

    Moisture quality continues to be a question within the Marginal Risk
    area as previously stated in prior outlooks. Surface observations
    show 50s dew points have made it as far north as the Red River in
    southern Oklahoma as of late Saturday evening. There remains some
    question just how far north (or deep) this moisture will be by late
    afternoon across Missouri/Illinois. Most 00z guidance suggests that
    50 F dew points will steadily spread into Missouri through the day
    today. However, afternoon sounding profiles suggest this moisture to
    be thin and potentially subject to mixing. Through the afternoon,
    weak convergence along the front and a mid-level capping inversion
    will likely prohibit convective development. As the short-wave
    ascent arrives in the evening, 00z HREF guidance suggest that at
    least isolated thunderstorms may develop (as seen in ensemble paint
    balls >40z dBZ and in calibrated thunder chances around 40-50%).
    Temperatures aloft will be rather cold (around -20 C at 500 mb).
    Even upper 40s F dewpoints will result in around 1000 to perhaps
    1500 J/kg MLCAPE by late afternoon/early evening. Given steepening
    lapse rate profiles and cold temperatures aloft, potential for a few
    instances of severe hail and strong to severe winds will be possible.

    ...Northern California/southwest Oregon...

    Convection is possible during the afternoon as mid-level
    temperatures cool in close proximity to the upper low off the coast.
    Filtered surface heating could allow for a few stronger storms to
    develop. Small hail and gusty winds are possible. Anvil-level flow
    will be quite weak which will likely lead to storms that are only
    strong briefly. The overall severe potential appears low.

    ..Thornton/Lyons.. 05/03/2026

    $$
    --- MultiMail/DOS
    * Origin: Project Scorpio TEST (618:250/6)
  • From Mike Powell@618:250/6 to All on Mon May 11 09:25:46 2026
    ACUS01 KWNS 111215
    SWODY1
    SPC AC 111213

    Day 1 Convective Outlook
    NWS Storm Prediction Center Norman OK
    0713 AM CDT Mon May 11 2026

    Valid 111300Z - 121200Z

    ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM THE COASTAL
    CAROLINAS INTO THE FLORIDA PENINSULA...AND ALONG THE CENTRAL GULF COAST...

    ...SUMMARY...
    Isolated severe storms with locally damaging wind gusts and hail are
    possible Monday afternoon from the coastal Carolinas into the
    Florida Peninsula, and along the central Gulf Coast.

    ...Carolinas...

    A large upper trough is present today over the eastern states, with
    a weak cold front sagging southward across the Carolinas. Ample
    low-level moisture is present to the south of the front from central
    SC into southeast NC, with dewpoints in the mid 60s. Pockets of
    daytime heating will destabilize this region, with the potential for
    isolated thunderstorm development by early afternoon. Low-level
    winds are veered and relatively weak, limiting frontal convergence
    and shear. A few strong storms may occur with locally gusty winds
    and hail. But the overall threat appears marginal.

    ...Eastern FL...

    Warm/moist conditions are expected today over the FL Peninsula with temperatures over the interior warming into the 90s. Deep westerly
    flow will focus convergence along the east-coast sea-breeze, leading
    to scattered afternoon thunderstorms. Sufficient deep-layer
    vertical shear may result in isolated strong-severe storms producing gusty/damaging winds and hail.

    ...Coastal LA/MS/AL...

    A convectively-aided shortwave trough over east TX will continue to
    track eastward across the central Gulf Coast region today. The
    combination of daytime heating and dewpoints in the mid-upper 60s
    will yield moderate CAPE values, leading to relatively widespread
    afternoon thunderstorms from southeast LA into southern MS/AL.
    Low-level winds are weak and lapse rates are rather weak.
    Nevertheless, cooler temperatures aloft and degree of instability
    will support a risk of occasionally intense cells capable of
    damaging winds and hail.

    ..Hart/Wendt.. 05/11/2026

    $$
    --- MultiMail/DOS
    * Origin: Project Scorpio TEST (618:250/6)
  • From Mike Powell@618:250/6 to All on Tue May 12 08:00:34 2026
    ACUS01 KWNS 121200
    SWODY1
    SPC AC 121159

    Day 1 Convective Outlook
    NWS Storm Prediction Center Norman OK
    0659 AM CDT Tue May 12 2026

    Valid 121300Z - 131200Z

    ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PARTS OF
    FLORIDA...AND FROM THE UPPER MISSISSIPPI VALLEY INTO KANSAS....

    ...SUMMARY...
    Severe storms will be possible at least on an isolated basis across
    parts of the Florida Peninsula today, and potentially from southeast
    Kansas into parts of the Great Lakes late this afternoon and early evening.

    ...KS to WI...

    A progressive shortwave trough is evident on morning water vapor
    imagery over MN. This feature will track across the Great Lakes
    region through the forecast period, with the associated surface cold
    front sagging into parts of the upper MS Valley. The air mass ahead
    of the front from WI into IL/MO/KS is initially quite dry with
    dewpoints only in the 30s/40s. However, strong southwesterly
    low-level winds will lead to slow moistening/destabilization of the
    pre-frontal air mass with a narrow corridor of MUCAPE around 500
    J/kg expected by late afternoon. Thunderstorm coverage will likely
    be sparse and high-based. However, a few strong/severe storms may
    form - capable of hail and gusty winds into early evening.

    ...FL...

    A moist and moderately unstable air mass remains in place over the
    FL Peninsula today. A well-defined shortwave trough over southern
    AL will track eastward today, resulting in sufficient large scale
    forcing for scattered afternoon thunderstorms. Low-level winds are
    veered, suggesting the most intense cells will be in vicinity of the
    east-coast sea-breeze. A few organized multicell or supercell
    storms are possible, posing a risk of damaging wind gusts and hail.

    ..Hart/Wendt.. 05/12/2026

    $$
    --- MultiMail/DOS
    * Origin: Project Scorpio TEST (618:250/6)
  • From Mike Powell@618:250/6 to All on Sat May 23 09:18:22 2026
    ACUS01 KWNS 231251
    SWODY1
    SPC AC 231250

    Day 1 Convective Outlook
    NWS Storm Prediction Center Norman OK
    0750 AM CDT Sat May 23 2026

    Valid 231300Z - 241200Z

    ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
    THE SOUTHERN PLAINS AND CENTRAL HIGH PLAINS...WESTERN AND CENTRAL
    GULF COAST...GEORGIA INTO SOUTH CAROLINA...AND ACROSS OHIO...

    ...SUMMARY...
    Isolated severe thunderstorms are possible today across the lower
    Mississippi Valley and into parts of Texas. Other isolated severe
    storms are possible in portions of the Southeast, Ohio, and the
    central High Plains.

    ...Southern High Plains...

    Weak mid-level flow and an ill-defined surface pattern aptly
    characterize the severe-potential setup for later today into the
    evening across this region. Residual low-level moisture and steep
    700-500 mb lapse rates (reference the 12 UTC Midland, TX raob; 8.7
    deg C/km) in combination with strong heating will result in moderate instability developing by mid-late afternoon. Scattered
    thunderstorms are forecast to develop from near the CO/OK-TX
    Panhandles border region southward into the Edwards Plateau.
    Isolated large hail and severe gusts will be the primary severe
    hazards with the stronger storms. Some clustering is expected
    during the evening before this activity diminishes by late evening.

    ...South-central and Southeast Texas/Southern Louisiana...

    In the coastal areas of the western and central Gulf, very moist air
    will be in place. Surface dewpoints in the lower to mid 70s F will
    contribute to moderate instability by midday. Thunderstorms will
    form along sea breeze boundaries during the early to mid afternoon.
    A few severe wind gusts and a brief tornado will be possible.
    Farther north over the Ark-La-Miss, some heating ahead of a
    north-south band of showers/thunderstorms associated with an MCV
    over OK, will contribute to a marginally supportive wind-damage
    risk. Have expanded low-wind probabilities to account for
    observational trends of a semi-organized band of storms continuing
    east into the Ark-La-Miss during peak heating.

    ...Georgia/South Carolina...

    A weak mid-level disturbance over MS/AL this morning will move east-northeastward today. Adequate heating of a moist boundary
    layer will yield 500-1000 J/kg MLCAPE by early afternoon and
    scattered showers/thunderstorms are forecast. Deep-layer shear will
    support some multicellular organization in the form of a few
    thunderstorm clusters. The stronger water-loaded downdrafts will
    potentially yield a localized wind-damage risk during the afternoon
    before this threat wanes by early evening.

    ...Central High Plains...

    Latest model guidance shows isolated thunderstorms developing late
    this afternoon within a belt of stronger cyclonic mid-level flow
    associated with a north-central U.S. larger-scale mid-level trough.
    The 30-40 kt 500-mb flow and steepened surface to 400-mb lapse rates
    may support a couple of locally stronger thunderstorms to develop
    towards early evening. Locally severe hail/wind will be the threat
    with these storms.

    ...Ohio...

    Southwesterly mid-level flow will be in place over the Ohio Valley
    and lower Great Lakes today. At the surface, an axis of low-level
    moisture will be located from eastern Kentucky into central and
    northern Ohio, where dewpoints will be in the mid to upper 60s F. As instability increases during the day, scattered thunderstorms are
    expected to develop and move northeastward across the instability
    corridor. RAP forecast soundings in central Ohio at 21Z have 0-6 km
    shear near 30 knots with 0-3 km storm-relative helicity around 150
    m2/s2. This could be enough for an isolated tornado threat.

    ..Smith/Weinman.. 05/23/2026

    $$
    --- MultiMail/DOS
    * Origin: Project Scorpio TEST (618:250/6)