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SPC Jan 8, 2024 0600 UTC Day 1 Convective Outlook

1 year 6 months ago

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1154 PM CST Sun Jan 07 2024 Valid 081200Z - 091200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS THE CENTRAL GULF COAST TONIGHT INTO EARLY TUESDAY MORNING... ...SUMMARY... Severe thunderstorms capable of strong wind gusts and tornadoes are expected from southeast Texas across the central Gulf Coast this afternoon into early Tuesday morning. Greatest severe potential is anticipated overnight from southeast Louisiana across southern Mississippi and southern Alabama, and into the western Florida Panhandle. ...Synopsis... A potent, positive-tilt mid-level shortwave centered over the Four Corners will undergo significant amplification as it emerges over the Southern Plains through the forecast period. South of the primary vort max, a 90-100 kt H5 jet streak will round the base of the trough and move quickly eastward, intensifying further, as it overspreads the mid-MS valley into early Tuesday. Coincident with the robust forcing aloft, a lee cyclone over northeast NM will quickly deepen below 1000 mb as it tracks eastward over the TX Panhandle and OK. South of the low, strong low-level mass response will rapidly advect a modifying Gulf air mass northward into portions of central/southeast TX and eventually across the central Gulf Coast. Strong low-level warm advection ahead of the intensifying upper-level and surface cyclone will support numerous showers and thunderstorms across the southern Plains and lower MS Valley today into early morning Tuesday. Strong kinematics and sufficient buoyancy within the onshore warm sector will support organized storms capable of all hazards, including a couple strong tornadoes. ...North TX into the ArkLaTex... Showers and embedded thunderstorms should be ongoing early this morning within a strong low-level warm advection regime ahead of the surface low and cold front in western north TX/OK. Area model soundings show weak and elevated buoyancy profiles atop a mostly stable surface layer ahead of the deeper returning surface moisture. Despite the marginal buoyancy, a narrow line of forced convection may evolve along the cold front and become capable of locally gusty/damaging wind gusts as it moves eastward from north TX into far southern AR and northern LA. ...Southeast TX to southwest LA... As the surface low continues to deepen over OK and western North TX, strong low-level mass response will rapidly draw a modifying Gulf air mass northward into south-central and southeast TX. Surface dewpoints will gradually rise into the low to mid 60s F as the air mass moves farther inland. Widespread cloud cover and warm advection showers will limit solar heating, but inhibition should weaken through the early afternoon as deep-layer ascent increases and gradual warming of the boundary layer supports 1200-2000 J/kg of MLCAPE. Scattered thunderstorms should gradually evolve from the initial low-topped showers within increasingly strong low-level and deep-layer shear profiles sufficient for supercells. A secondary surface low along the advancing warm front may also locally back surface winds, favoring strong low-level mesocyclones with the potential for damaging gusts and a few tornadoes. Additional storms are likely to develop later in the afternoon as the surface cold front approaches from the west. Behind the secondary surface low, veered low-level flow suggests a more linear orientation may evolve with upscale growth of the new convection into a broken line/QLCS with greater potential for damaging wind gusts. Still, 0-1 km shear in excess of 30 kt may support some risk for line embedded circulations with enhanced damaging gust or tornado potential into the evening and overnight hours. ...Central Gulf Coast tonight into early Tuesday... An initial round of elevated showers and thunderstorms is expected to develop by early to mid afternoon over parts of the central Gulf coast ahead of the warm front moving onshore. As the Gulf air mass gradually moves inland, increasing surface dewpoints will allow for moderate buoyancy to develop coincident with a strong increase in mid and low-level shear profiles ahead of the advancing upper trough. A 60-70 kt low-level jet will continue to support strong warm advection and the development of additional thunderstorms ahead of the main convective line to the west into the evening and overnight hours. A few supercells may evolve ahead of the line over parts of southern MS, southwest AL and the western FL Panhandle within a very strongly sheared environment. STP values of 3-5 on area model soundings suggest the potential for a couple of strong tornadoes. Damaging wind gusts and line-embedded tornadoes also appear likely as the QLCS advances quickly from west to east. ..Lyons/Grams.. 01/08/2024 Read more