SPC Mar 10, 2025 Day 4-8 Severe Weather Outlook
Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0354 AM CDT Mon Mar 10 2025 Valid 131200Z - 181200Z ...DISCUSSION... ...Day 4/Thu - Southeast... A shortwave upper trough will move across the Southeast on Thursday. Stronger deep-layer flow will mainly be focused over the Gulf. However, cooler temperatures aloft will support weak instability and a strong storm or two may occur over portions of AL/GA and the FL Panhandle. Overall severe potential appears limited. ...Day 5/Fri - ArkLaTex to the Mid/Lower MS Valley vicinity... A regional outbreak of severe storms is forecast late Friday afternoon into the overnight hours. An intense upper cyclone will deepen as it ejects northeast from the central/southern Plains to the Upper Midwest by Saturday morning. A 100+ kt 500 mb jet streak will move across OK into the Ozark Plateau during the late afternoon and evening, before lifting north across the Mid-MS Valley overnight. At the surface, a rapidly deepening surface low will move across the central Plains to the Upper Midwest, with a cold front surging east across the region from late afternoon into Saturday morning. Deeper Gulf moisture will be confined to the I-20 corridor Friday morning. However, intense low-level flow will quickly transport moisture northward through the mid-MS Valley. Surface dewpoints greater than 60 F will likely remain south of the MO Bootheel vicinity, with a broader area of more modest moisture as far north as northeast IA/southwest WI and northern IL. While moisture will be less favorable with northward extent, strong large-scale ascent, intense deep-layer flow and a surging cold front will likely be sufficient for severe convection even amid weak instability. Further south from the ArkLaTex vicinity to the Lower MS Valley, better quality moisture is expected to overlap intense shear. Overall, this pattern will support all severe hazards, with a potential mixed mode evolution (QLCS and supercells). The north and east extent of severe potential remains a bit uncertain either due to moisture concerns and/or spread among various guidance in timing and position of key features. Severe probabilities will likely be refined over the coming days as these features become better resolved. ...Day 6/Sat - Southeast... The Upper Midwest cyclone will eject northeast into Ontario on Saturday. Meanwhile the base of the larger-scale upper trough over the Plains ejects east toward the Lower MS Valley and Southeast. This will maintain strong deep-layer southwesterly flow across the region, with an intense low-level jet expected to develop by late afternoon as stronger height falls overspread the Deep South. Ongoing convection at the beginning of the period from the Lower OH Valley toward northern MS/LA adds some uncertainty regarding how the airmass will destabilize (especially with northward extent). However, it appears likely that a very favorable corridor of rich boundary layer moisture will overlap strong shear from central/southern MS into northern AL ahead of a cold front expected to surge across the area during the evening. This overall pattern appears favorable for both supercells and an eventual QLCS. ...Day 7/Sun - Eastern states... The upper trough over the central U.S. will lift northeast over the eastern states on Sunday. Some severe potential is possible given strong deep-layer flow atop a moist boundary layer ahead of the eastward-advancing cold front. However, destabilization may be limited by widespread training precipitation.
About The Author
