Blue Flower

Outlook (Main)

Storm Prediction Center
SPC Forecast Products
  1. No watches are valid as of Thu May 26 05:40:01 UTC 2022.
  2. No Mesoscale Discussions are in effect as of Thu May 26 05:40:02 UTC 2022.
  3. SPC 0100Z Day 1 Outlook
    Day 1 Outlook Image
    Day 1 Convective Outlook  
    NWS Storm Prediction Center Norman OK
    0754 PM CDT Wed May 25 2022
    
    Valid 260100Z - 261200Z
    
    ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM THE LOWER
    MISSISSIPPI VALLEY TO THE SOUTHERN GREAT LAKES...
    
    ...SUMMARY...
    Isolated strong to severe thunderstorms remain possible, primarily
    across the central Gulf Coast states tonight.
    
    ...01z Update...
    
    Center of upper low is currently located over northern OK. This
    feature will move slowly northeast tonight as stronger flow advances
    downstream into the lower MS/western TN Valley region. While bands
    of strong/severe convection have developed well ahead of this
    feature, primary surface front may become more convectively active
    later this evening across AR/LA. Both LCH and LZK exhibited
    weak/minimal inhibition in their 00Z soundings and isolated
    thunderstorms are now forming along the boundary across AR. As weak
    mid-level height falls spread across this region there appears to be
    some chance for renewed convection along the front later this
    evening. Earlier corridor of strong/severe thunderstorms across
    MS/AL has shifted a bit downstream and a few robust storms may
    linger across this region with some attendant threat for locally
    strong winds or perhaps a brief tornado.
    
    Elsewhere, scattered showers/thunderstorms persist from the TN
    Valley into the southern Great Lakes region. Overall trends have
    been down with this activity but modest shear and ample buoyancy
    will likely continue to support at least a few robust updrafts this
    evening. Primary risk appears to be locally gusty winds.
    
    ..Darrow.. 05/26/2022
    
    
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  4. SPC 1200Z Day 1 Outlook
    Day 1 Outlook Image
    Day 1 Convective Outlook  
    NWS Storm Prediction Center Norman OK
    1233 AM CDT Thu May 26 2022
    
    Valid 261200Z - 271200Z
    
    ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS PORTIONS OF THE
    PACIFIC NORTHWEST...GEORGIA INTO THE WESTERN CAROLINAS...AND THE
    UPPER OHIO RIVER VALLEY...
    
    ...SUMMARY...
    Isolated to widely scattered severe thunderstorms may occur Thursday
    over Ohio/eastern Kentucky, northeastern Georgia into the far
    western Carolinas, and parts of northeastern Oregon, southeastern
    Washington, and Idaho. Severe wind gusts and large hail should be
    the primary hazards.
    
    ...Synopsis...
    An upper-level low over the central CONUS is evident in
    early-morning water vapor imagery. This feature will continue to
    drift east into the southern/central Appalachians over the next 24
    hours. As this occurs, a diffuse surface low and attendant cold
    front will shift into the OH River Valley and southeastern U.S.
    respectively. 00 UTC RAOBs from across these regions sampled modest
    mid-level lapse rates (generally between 6-7 C/km), but a broad
    swath of boundary-layer mean mixing ratios between 10-13 g/kg across
    the region coupled with diurnal warming will support adequate
    buoyancy for convection by early afternoon. To the west, an
    upper-level wave off the West Coast will move onshore later today.
    Height falls across the Pacific Northwest and the approach of a
    mid-level cold front will support thunderstorm development late in
    the afternoon/evening.
    
    ...Southeast...
    A cold front currently moving across the lower MS River Valley is
    expected to continue eastward into the Southeast today.
    Thunderstorms will likely be ongoing at the start of the period
    along the Gulf Coast, but will increase in coverage along the front
    through the late morning and early afternoon across AL into GA.
    Although moist profiles and modest mid-level lapse rates will limit
    buoyancy to a degree, MLCAPE should be adequate for increasingly
    robust updrafts by early afternoon. Increasing deep-layer shear off
    the boundary, as well as strengthening 850-700 mb flow, will support
    the potential for a few cells and/or organized segments along the
    front. A Slight risk is introduced for portions of central GA into
    the western Carolinas where the potential for such organized
    segments (and an attendant damaging wind threat) appears greatest.  
    
    
    A diffuse wedge front, noted in early-morning observations across
    the Carolinas, is expected to lift north as a warm frontal zone
    through the day in response to increasing southerly flow.
    Thunderstorms may develop along this boundary during the afternoon.
    A few stronger, more organized cells are possible, but storm motions
    along the boundary and the possibility of destructive storm
    interference may limit this potential.
    
    ...Upper OH River Valley...
    Broad ascent ahead of the upper low overlaid with a mid-level
    convergence zone will support isolated to widely scattered
    thunderstorms from IL into the upper OH River Valley. Modest low to
    mid-level lapse rates will limit buoyancy despite 55-65 F dewpoints
    already in place. However, forecast soundings show adequate CAPE
    profiles to utilize the stronger flow aloft with 35-45 knots of
    effective bulk shear likely across this region. The isolated to
    scattered nature of convection should allow for at least a few
    organized cells and/or linear segments. Narrow CAPE profiles may
    limit the overall hail potential to a degree, but 30-40 knot flow
    within the lowest 1 km will support a damaging-wind potential.
    Recent guidance continues to suggest that the greatest convective
    coverage (and hence increased wind threat) will reside across
    northeast KY into OH and far western WV near the exit region of the
    upper jet.
    
    ...Pacific Northwest...
    00 UTC soundings from across the Pacific Northwest have shown a
    general increase in mid-level moisture over the past 12 hours as
    deep-layer onshore flow increases. Additionally, mid-level lapse
    rates have steepened as broad, but weak, ascent overspreads the
    region ahead of the upper-level wave. This trend will continue
    through the day and, when coupled with daytime heating, should
    support around 500 J/kg MLCAPE by late afternoon. While buoyancy may
    be somewhat limited, straight hodographs off an initiating cold
    front will promote discrete cells, including the potential for a few
    supercells, from northeast OR into northern ID. Large hail appears
    probable with these cells, and steep low-level lapse rates with a
    1-2 km dry sub-cloud layer will support the potential for severe
    wind gusts.
    
    ..Moore/Darrow.. 05/26/2022
    
    
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  5. SPC 0600Z Day 2 Outlook
    Day 2 Outlook Image
    Day 2 Convective Outlook  
    NWS Storm Prediction Center Norman OK
    1236 AM CDT Thu May 26 2022
    
    Valid 271200Z - 281200Z
    
    ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE CAROLINAS
    NORTHWARD INTO PENNSYLVANIA AND NEW JERSEY...
    
    ...SUMMARY...
    Widely scattered severe thunderstorms are possible on Friday from
    the Carolinas northward into eastern Pennsylvania and New Jersey. 
    Damaging gusts and a couple of tornadoes are the primary threats
    with the stronger storms in the Chesapeake Bay region.
    
    ...Synopsis...
    A mid-level low initially over southern IN will move
    east-northeastward into central PA and weaken into an open trough by
    early Saturday.  A composite boundary will push east across the
    Appalachians and much of the eastern U.S. during the period. 
    Farther west, a belt of low-amplitude, southwesterly mid-level flow
    will spread across the northwestern CONUS as a mid-level ridge
    weakens over the central U.S.
    
    ...Southeast northward through the Mid-Atlantic states and
    NY/VT/ME...
    Model guidance is consistent in depicting scattered
    showers/thunderstorms to be ongoing Friday morning from parts of the
    central Appalachians southward into the Carolinas and northeast Gulf
    of Mexico.  Ahead of the convection, moisture advection via moderate
    southerly low-level flow will contribute to dewpoints ranging from
    the lower-mid 60s in the Northeast, to the upper 60s to lower 70s
    from the Chesapeake Bay vicinity and south.  Diurnal heating will
    yield 1000-2000 J/kg MLCAPE from the Mid-Atlantic states southward
    into coastal SC.  An extensive broken squall line (linear clusters
    and transient supercells) will likely develop during the afternoon
    into the early evening.  Ample deep-layer shear for storm
    organization will exist from the Canadian border southward into the
    Mid-Atlantic states with 30-50 kt effective shear forecast.  Weaker
    flow is progged farther south (20-30 kt effective shear) but
    organized multicells will be possible.  Isolated large hail could
    accompany the stronger cells.  The concentration of 50-65 mph gusts
    and wind damage will probably be highest in the
    Mid-Atlantic/Chesapeake Bay vicinity.  There, forecast hodographs
    and moist low levels will conditionally yield a several-hour period
    favorable for storm-scale rotation (supercellular or QLCS) and an
    associated risk for a few tornadoes.  This activity will likely
    weaken during the evening.
    
    ...MT/WY into western Dakotas...
    A series of weak mid-level disturbances is forecast to move quickly
    east across the northern Rockies into the northern Great Plains.  As
    a result, an area of low pressure will likely develop over the
    western Dakotas by late afternoon.  A marginally moist boundary
    layer beneath steep mid-level lapse rates will yield 500-1000 J/kg
    SBCAPE by late afternoon.  Isolated to widely scattered
    thunderstorms will probably develop during the late afternoon/early
    evening.  Isolated severe gusts and hail may accompany the stronger
    storms.
    
    ..Smith.. 05/26/2022
    
    
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