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  "path": "/products/md/md0640.html",
  "publishedAt": "2026-05-04T23:36:03.000Z",
  "site": "https://www.spc.noaa.gov",
  "tags": [
    "Read more"
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  "textContent": "MD 0640 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR SOUTH-CENTRAL ILLINOIS AND SOUTHERN INDIANA\n\n\n\n\n    Mesoscale Discussion 0640\n    NWS Storm Prediction Center Norman OK\n    0629 PM CDT Mon May 04 2026\n\n    Areas affected...South-central Illinois and Southern Indiana\n\n    Concerning...Severe potential...Watch possible\n\n    Valid 042329Z - 050200Z\n\n    Probability of Watch Issuance...40 percent\n\n    SUMMARY...An isolated severe threat for large hail is expected to\n    continue for a few hours across south-central Illinois, and may\n    affect southern Indiana. The for weather watch issuance is\n    uncertain.\n\n    DISCUSSION...A couple cells have recently develop to the northeast\n    of the St. Louis metro. The activity is located along the eastern\n    edge of a pocket of moderate instability, where the RAP has MLCAPE\n    around 1000 J/kg. The storms are being supported by an area of\n    low-level convergence and by large-scale ascent associated with a\n    subtle shortwave trough, evident on water vapor imagery. The WSR-88D\n    VWP near St Louis has effective shear in the 30 to 40 knot range,\n    and the RAP shows very steep mid-level lapse rates exceeding 7.5\n    C/km. This should be favorable for large hail with supercells that\n    form. However, a capping inversion is evident over much of\n    southeastern Illinois and southern Indiana. Also, RAP suggests that\n    instability is very weak in this same area. For this reason, the\n    storms are expected to remain elevated, and the eastern extent of\n    the severe threat is uncertain.\n\n    ..Broyles/Hart.. 05/04/2026\n\n    ...Please see www.spc.noaa.gov for graphic product...\n\n    ATTN...WFO...LMK...IND...PAH...ILX...LSX...\n\n    LAT...LON   38058802 38218956 38489008 38859021 39299012 39638974\n                39798899 39748736 39618654 39338617 38828613 38318631\n                38088688 38058802\n\n    MOST PROBABLE PEAK WIND GUST...UP TO 60 MPH\n    MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN\n\n\n\nRead more",
  "title": "SPC MD 640"
}