Severe Storm Outlook Narrative (AC)
Issued by NWS
Issued by NWS
991 ACUS02 KWNS 181742 SWODY2 SPC AC 181741 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1241 PM CDT Sat May 18 2024 Valid 191200Z - 201200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF WESTERN AND CENTRAL KANSAS... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE EAST COAST OF FLORIDA... ...SUMMARY... Severe thunderstorms are most likely across parts of Kansas Sunday afternoon and evening. Significant damaging gusts, large to very large hail, and a few tornadoes all appear possible. Large hail is also probable along parts of the east coast of Florida. ...Synopsis... A shortwave trough will slowly exit the southeastern U.S. coast on Sunday. Across the West, another broad upper-level trough will intensify and dig southward. Shortwave perturbations are expected to eject into the central Plains early Sunday morning and near the Raton Meso into western Kansas later in the afternoon. At the surface, a weak surface low will move through southeastern Georgia into North Florida. A surface boundary may sag farther southward into the Florida Peninsula along with a sea breeze front developing by the afternoon. In the High Plains, two surface lows will deepen, one in the southern High Plains and another in the central High Plains near the Black Hills. ...Central into Southern Plains... Some convection is expected to be ongoing early in the period along the Kansas/Nebraska border into eastern Nebraska in association with a low-level jet and the weak shortwave trough moving through the region. This activity will shift north and east with time as the trough passes. By the afternoon, a dryline forecast to develop from southwest Kansas into the Texas Panhandle/western Oklahoma. A capping inversion should keep development from occurring until the secondary shortwave ejects during the afternoon. Storms that initially develop in Kansas will likely be supercells capable of all severe hazards, including very large hail. The uncertainty in this scenario will be how long storms will remain discrete. Storms that can form farther east along the dryline would have the greatest potential to remain discrete for longer. However, there is a signal for convection to develop within the Raton Mesa and eventually intensify as it encounters greater surface moisture to the east. These storms would likely be more outflow dominant initially and could lead to the quicker clustering that most guidance shows in Kansas. Forecast soundings from CAMs show strong cold pool development and hints of a strong rear inflow jet, suggesting potential for a strong MCS capable of significant wind gusts. Farther south into western Oklahoma, storm coverage is much less certain on account of stronger capping and weaker forcing. Should a storm develop, all severe hazards would be possible. Currently, a discrete storm appears most likely in northwest Oklahoma on the southern fringe of the mid-level ascent. ...Florida... Storms appear likely to develop along the southward sagging surface boundary. However, strong heating is expected along the east coast of Florida with storms forming along the sea breeze in the afternoon. With the generally favorable timing of the shortwave trough, shear should be sufficient for supercells and temperatures aloft should be cold enough (around -10 C) to support a threat for large hail. Farther west, storms are not expected to be as organized, but isolated damaging winds and large hail are still possible. ...Western Nebraska/western South Dakota... The northern surface low will deepen and help advect mid to perhaps upper 50s F dewpoints into the region. Storms are expected to develop during the afternoon. Large hail and severe wind gusts will be the main hazards. The larger surface temperature/dewpoint spreads and weaker shear than farther south may lead to less organized storms. As such, will continue with a Marginal hail/wind risk. ..Wendt.. 05/18/2024 $$