Severe Storm Risk - Siluria, AL

There is a Marginal Severe Storm Risk for your location. Continue reading for today's outlook from the National Weather Service's Storm Prediction Center. -------------------- National Severe Storm Outlook THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE SOUTHEAST...MONTANA...AND NORTH DAKOTA SUMMARY Scattered damaging winds should occur across parts of the Southeast this afternoon/early evening. Scattered large hail is forecast across portions of Montana and North Dakota this afternoon and evening. Isolated strong to severe thunderstorms may also occur today across parts of the northern Great Basin, northern/central Plains, and Missouri Valley to the Ozarks. Southeast/Lower Mississippi Valley Recent visible satellite imagery shows mostly clear skies across GA/SC late this morning, with surface temperatures already in the mid/upper 80s to low 90s. A weak front is draped from northwest to southeast from the southern Appalachians to the Atlantic Coast, with generally low to mid 70s surface dewpoints present to its south. Continued diurnal heating of this moist airmass will support the development of moderate to strong instability (greater with southward/westward extent into GA/AL and north FL). Compared to the past couple of days, this region will be displaced from the stronger mid-level west-northwesterly flow present across the Mid-Atlantic/Northeast. Corresponding deep-layer shear is expected to remain rather modest (less than 25 kt), with only loosely organized updrafts forecast. Even with these kinematic limitations, steepening low-level lapse rates through the afternoon may still promote isolated to scattered damaging winds with clusters that develop and spread south-southeastward through the early evening. Isolated hail may also occur with the more robust cells that can develop initially. The damaging wind threat should be more isolated with westward extent into the lower MS Valley compared to GA and the Carolinas, where the Slight Risk has been maintained with some expansion. Northern Great Basin into the Northern Rockies/High Plains A closed mid/upper-level low over the Pacific Northwest and British Columbia will pivot towards the northern Rockies through the period, with a belt of enhanced mid-level flow overspreading the northern Great Basin into the northern Rockies and adjacent High Plains in MT. At the surface, mostly cloudy conditions are present over much of western/central MT this morning. Even so, recent NAM/RAP forecast soundings across this region show supercell profiles later this afternoon and evening as mid/upper-level winds foster strong deep-layer shear. Current expectations are for multiple supercells to develop initially over the higher terrain and spread quickly northeastward. While there is still some uncertainty regarding boundary-layer destabilization, sufficient MUCAPE is forecast to support supercell maintenance into the adjacent High Plains through the evening. Large hail should be the main threat with this activity (with some 2+ inches possible given the very favorable deep-layer shear), but isolated severe gusts may also occur. The Slight Risk has been adjusted/expanded a little eastward in MT based on latest short-term guidance trends. High-based thunderstorms may also pose an isolated threat for severe gusts across parts of the northern Great Basin this afternoon. Northern/Central Plains into the Upper Midwest/Missouri Valley and Ozarks Ongoing and likely elevated supercells with a threat for large hail across parts of western ND are being aided by a subtle mid-level shortwave trough cresting the upper ridge that is anchored over the central CONUS. Favorable lapse rates aloft and modestly enhanced mid/upper-level southwesterly flow is likely supporting updraft organization/intensity with this ongoing activity. The airmass downstream across central/eastern ND should gradually destabilize through the afternoon, with a moist low-level airmass present to the east of a weak surface low over eastern MT/southwest ND/northwest SD. It remains unclear whether these ongoing supercells will be maintained farther east across ND, but given the favorable airmass and sufficient deep-layer shear present, have opted to add a targeted Slight Risk for the large hail potential. Additional convection is occurring farther south in SD, southwest MN/northwest IA, and northeast NE in association with a mid-level vorticity maximum evident on water vapor satellite imagery moving eastward across SD/NE. There is a narrow corridor of greater instability present across this region southward to the Ozarks, generally along/near a weak surface front. Isolated hail may occur with the stronger cores in the short term, but it remains unclear if convection will be able to form into a southward-moving cluster across eastern NE/western IA later this afternoon and evening. If this does occur, then a greater threat for severe/damaging winds would exist. Have deferred a possible upgrade to Slight Risk given the uncertainty with how ongoing convection will evolve/impact the developing warm sector, and due to the presence of the large-scale mid/upper-level ridge and generally modest flow aloft. A separate area of high-based thunderstorms that should develop this afternoon along/east of a surface lee trough across the central High Plains could produce occasional hail and severe gusts, even as deep-layer shear remains modest.