Storm Prediction Center Day 4-8 Severe Weather Outlook Page (2024)

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 ZCZC SPCSWOD48 ALL ACUS48 KWNS 230859 SPC AC 230859 Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0359 AM CDT Tue Apr 23 2024 Valid 261200Z - 011200Z ...DISCUSSION... A complex but active pattern is expected from D4/Friday through D6/Sunday, as multiple mid/upper-level shortwave troughs impinge upon a moist and unstable environment extending from the southern/central Great Plains into parts of the Midwest and Mississippi Valley. ...D4/Friday - Central/southern Plains into the mid MS Valley... A negatively tilted shortwave trough is forecast to move northeastward from the Great Plains toward the mid/upper MS Valley on Friday. Most guidance suggests that convection developing late in the D3/Thursday period will be ongoing Friday morning, potentially posing an organized severe threat as it moves eastward. The influence of early convection on warm sector evolution by Friday afternoon/evening remains uncertain, but in general, moderate destabilization will be possible along the Pacific front/dryline in the wake of early convection, with some intensification of early storms also possible farther east. Details regarding storm mode remain uncertain at this forecast range, but in general, severe storms capable of producing large hail, damaging winds, and a few tornadoes will be possible across a broad region from the eastern Great Plains into the mid MS Valley. ...D5/Saturday - Central/southern Plains into the Midwest/mid MS Valley... The negatively tilted shortwave trough and attendant occluding surface cyclone are forecast to gradually weaken as they move across the upper Great Lakes region on Saturday. Depending on timing of the departing cyclone and magnitude of diurnal destabilization, some severe-thunderstorm threat could evolve in advance of this system through the afternoon across parts of WI/IL into MI, but confidence remains too low to include 15% probabilities for this area. Meanwhile, another strong shortwave trough is forecast to eject across parts of the central/southern Plains Saturday afternoon and evening, accompanied by strong surface cyclogenesis across the central High Plains. Moderate to locally strong instability may redevelop along/east of the dryline across central/western KS/OK into north TX, as low-level and deep-layer shear strengthen through the day. The synoptic pattern depicted by much of the extended-range guidance is suggestive of an active severe thunderstorm episode along/ahead of the dryline, though some guidance (notably recent runs of the ECMWF) suggest potential for early development across parts of OK/north TX, which could complicate the scenario by late afternoon/evening. Some severe threat could spread toward parts of the mid MS Valley late in the period. ...D6/Sunday - ArkLaTex into parts of the Midwest... Predictability begins to decrease by late in the weekend, though in general, a mid/upper-level trough and attendant surface low are forecast to move from the central Plains toward the upper Great Lakes region. A corridor of severe thunderstorm potential is forecast to extend south-southwestward from the surface low, as a trailing cold front moves through a moist, unstable, and favorably sheared environment. A 15% area has been added where confidence is currently greatest in severe-thunderstorm potential Sunday afternoon and evening. ..Dean.. 04/23/2024 CLICK TO GET WUUS48 PTSD48 PRODUCT