Rio Grande Valley/south central TX this afternoon/evening... Boundary-layer dewpoints in the low 70s have spread westward across south central TX to the Rio Grande, beneath very steep midlevel lapse rates near 9 C/km. The combination of surface heating in cloud breaks by afternoon, low-level ascent along a stalled front across the Edwards Plateau, and upslope flow into the Serranias Del Burro (west of DRT), will support at least widely-scattered thunderstorm development by mid afternoon. The initial storms should be discrete, with some clustering possible later this evening as a result of cell mergers/interactions of right- and left-moving supercells. MLCAPE near 4000 J/kg and effective bulk shear of 40-50 kt with long hodographs will favor supercells capable of producing isolated very large to giant hail (3-4" diameter) and damaging gusts. Additionally, low-level hodograph curvature/shear may remain sufficient for an isolated tornado late this afternoon/evening. ...
Central/eastern NC this afternoon/evening... A subtle midlevel trough will move over NC this afternoon, as a surface cold front moves southward from VA into NC. Surface heating in cloud breaks will boost afternoon temperatures to near 80 F with boundary-layer dewpoints in the low-mid 60s along and south of the front, resulting in MLCAPE of 500-1000 J/kg this afternoon across NC. Scattered thunderstorm development is expected along and a little south of the front as buoyancy is maximized and convective inhibition is removed by mid afternoon, and storms will subsequently spread east-southeastward across NC through this evening. Though midlevel lapse rates will not be steep, deep-layer vertical shear will be sufficient for a few organized clusters/supercells capable of producing damaging outflow gusts and marginally severe hail. ...
Northeast TX to northwest LA through mid afternoon... Elevated storms formed this morning over the Red River Valley in association with warm advection and a subtle midlevel speed max moving eastward. The storms may persist for a few more hours while moving along the northeast edge of the buoyancy gradient (MUCAPE of 1000-2000 J/kg), given the potential to maintain some organized structures with effective bulk shear near 50 kt for the elevated parcels. Occasional large hail will be the main threat. ...
Southern LA this afternoon... A cluster of storms with occasional bow and embedded supercell structures is now moving across the New Orleans area. The near-storm environment is somewhat favorable for organized storm structures along the residual outflow boundary from overnight convection. However, the storms appear to have peaked in intensity earlier this morning, and the potential for any substantial uptick this afternoon appears too uncertain to warrant any change to the Marginal risk assessment. ..Thompson/Moore.. 05/10/2021 Read more LIVE: spc.noaa.gov
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NWS SPC Convective Outlook provided by Arlingtoncardinal.com/weather
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Arlingtoncardinal.com/snow
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