Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0357 AM CDT Sat Apr 15 2023 Valid 181200Z - 231200Z ...DISCUSSION... ...Tuesday/Day 4... On Tuesday, an upper-level ridge is forecast to move eastward across the Great Plains. In its wake, southwest mid-level flow will become established, and a low-level jet will strengthen. In response, low-level moisture is expected to return northward into the southern and central Plains from Tuesday into Tuesday night. As the airmass moistens in the southern Plains, isolated thunderstorms will be possible near a strengthening low-level jet. Although the storms appear to likely be elevated, a hail threat could accompany the stronger cells ...Wednesday/Day 5 to Thursday/Day 6... Moisture return is forecast to continue across the southern and central Plains on Wednesday, with a dryline setting up across west-central Oklahoma and central Kansas during the day. Isolated thunderstorm development will be possible to the east of the dryline during the afternoon and evening. Model forecasts now move a shortwave trough across the southern Plains Wednesday night, which would coincide with the greatest potential for isolated severe storms. On Thursday, the shortwave trough is forecast to become negatively tilted, moving northeastward across the southern and central Plains. The newest runs drive the dryline quickly eastward during the day. Scattered thunderstorms appear likely to develop near the moisture and instability axis from the Ozarks southwestward into the Ark-La-Tex. During the midweek time-frame, the potential for severe thunderstorms appears greatest on Thursday, as the shortwave trough moves through the central U.S. Have shifted the 15 percent area eastward into southern Missouri and Arkansas to account for the faster movement of the upper-level system. ...Friday/Day 7 and Saturday/Day 8... From Friday into Saturday, the models move an upper-level trough across the eastern half of the nation. An associated cold front is forecast to move from the Mississippi Valley to the Eastern Seaboard. Thunderstorm development will be possible along the front on both days. More instability is forecast ahead of the front on Friday, suggesting a potential for isolated severe storms during the afternoon and evening. Based on the ECMWF, the greatest severe potential would exist ahead of the trough in the Tennessee Valley. However, the various model solutions are widely dispersed suggesting that uncertainty is substantial late in the period.
