Convective Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1224 PM CDT Sun Apr 11 2021 Valid 121200Z - 131200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE TEXAS HILL COUNTRY.... ...SUMMARY... Isolated severe thunderstorms are possible in the Texas Hill Country on Monday with a threat for large hail and severe wind gusts. ...Synopsis... A few areas of mid-level low pressure will be present across the northern Plains and Great Lakes Monday morning. These low pressure areas will shift eastward/southeastward through the day. A strong mid-level jet will dive southward along the West Coast through the day Monday and act to amplify the western CONUS trough. In addition, a weak shortwave is expected to eject from this broader trough Monday afternoon across portions of Texas. At the surface, a cold front will sink southward across Texas through the day. Some severe storms may form on this cold front Monday afternoon/evening with a threat for large hail and severe wind. ...Texas Hill Country... Low-level flow off the Gulf of Mexico will transport moisture northwestward Monday morning and afternoon. Surface dewpoints are expected to increase to the low to mid 60s by mid to late afternoon with temperatures in the low to mid 80s. This will likely result in 2000+ MLCAPE ahead of a southward moving cold front. A weak shortwave/height falls aloft combined with convergence along this front may provide enough forcing for a few strong to severe storms Monday afternoon/evening. Moderate to strong instability combined with around 50 knots of effective shear will provide an environment favorable for supercells with the potential for large hail and damaging winds. The southward sagging nature of the cold front could undercut the storms and limit storm longevity, especially on the northern portions of the marginal risk, but steep mid-level lapse rates would still support elevated convection and a hail threat. Additional storms may form in an upslope regime near Del Rio and move off the terrain for a few hours in the evening before encountering a capped airmass with eastern extent. Questionable storm coverage is the primary mitigating factor to a higher risk category at this time, but if more storms appear likely (such as suggested by the 12Z HRRR and NSSL WRF), a slight risk may be warranted in later outlooks. ..Bentley/Gleason.. 04/11/2021Read more
Updated 11 April 2021 | 12:27 pm
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1129 AM CDT Sun Apr 11 2021 Valid 111630Z - 121200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON ACROSS CENTRAL FL... ...SUMMARY... Damaging winds, a tornado or two, and isolated large hail are expected this afternoon across central Florida. The threat for a few damaging gusts will also shift southward into south Florida later this afternoon/evening. ...Central/south FL this afternoon/evening... A large cluster of thunderstorms that formed early this morning across the northeast Gulf of Mexico is evolving into a bowing MCS as it moves onshore near Tampa. The storms will likely move along an outflow boundary across central FL through the day, with the storms forcing the outflow southward with time. Surface heating and increases in low-level moisture south of the boundary, along with 50 kt west-southwesterly midlevel flow, will support the threat for swaths of damaging gusts with the bowing segments. A tornado or two may also occur with embedded circulations where the bowing segments interact with the east-west oriented outflow boundary. The threat for at least isolated damaging winds will shift southward with time along the outflow boundary, spreading into south FL this afternoon/evening. ...Eastern NC into the Mid-Atlantic this afternoon/evening... A lead shortwave trough is rotating northeastward over the Mid-Atlantic as of midday, with little forcing for ascent (or weak subsidence) in its wake. Given surface heating and lingering low-level moisture along and ahead of a cold front, a few storms may still develop this afternoon, with the more probable area from VA into south central PA. There will be marginally sufficient vertical shear and buoyancy for a low-end threat for damaging winds and/or large hail with the strongest storms this afternoon/evening. ..Thompson/Guyer.. 04/11/2021Read more
Updated 11 April 2021 | 11:33 am