Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0355 AM CDT Sat Jul 24 2021 Valid 271200Z - 011200Z ...DISCUSSION... ...Tuesday/Day 4 to Thursday/Day 6... A large upper-level high will remain anchored across much of the western and central United States during the mid week time-frame. Northwest mid-level flow is forecast across much of the Mississippi Valley and eastern U.S. At the surface, a moist axis is forecast to be located in the mid to upper Mississippi Valley, with a front moving southeastward across the upper Midwest on Wednesday and Thursday. Thunderstorm development will be possible across the northern edge of the moist corridor Tuesday afternoon and evening, with storms also possible along and ahead of the front Wednesday and Thursday. Although instability and shear should be sufficient for a severe threat across parts of the mid to upper Mississippi Valley each afternoon and evening, uncertainty is too high to warrant adding a threat area at this time. ...Friday/Day 7 and Saturday/Day 8... Northwest mid-level flow is forecast to continue from the north-central states to the Eastern Seaboard on Friday and Saturday. At the surface, a cold front is forecast to move southward from the Tennessee Valley on Friday into the Southeast on Saturday. Moderate instability is forecast along and ahead of the front each afternoon, with thunderstorm development possible near the front. Although deep-layer shear may remain relatively weak across most of the Southeast, an isolated severe threat can not be ruled out due to the thermodynamic environment. Mesoscale uncertainty is high concerning any specific scenario this far in advance. Read more LIVE: spc.noaa.gov
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