Convective Outlook
SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1113 AM CDT Mon Apr 29 2024 Valid 291630Z - 301200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS THROUGH LATE AFTERNOON ACROSS THE LOWER MS VALLEY...SOUTH TX...AND SOUTHEAST LOWER MI... ...SUMMARY... Marginally severe wind gusts and hail will be possible today across south Texas, the lower Mississippi Valley and southeast Lower Michigan. ...LA/MS/AL... A decaying linear MCS is moving slowly southeastward across southern LA, with the most active part of the line well offshore. The leading outflow boundary extends northward across southeast LA into central MS, with a warm/moist low-level air mass in place to the east. Some rejuvenation of thunderstorms along this line is expected this afternoon, with storms tracking eastward toward southwest AL this evening. Mid-level lapse rates are weak in this area, along with weak to moderately strong low to mid-level wind fields. This suggests some risk of gusty or possibly damaging winds with these storms, but the threat is expected to remain rather isolated. ...Southeast Lower MI... Visible satellite imagery shows strong heating occurring over southeast Lower MI today, but with a broad area of clouds and light precipitation approaching from the southwest. Several morning CAM solutions show scattered afternoon thunderstorms developing along the leading edge of this cloud deck. Storms will sweep across the area rather quickly, with steepening low-level lapse rates posing a risk of locally gusty/damaging wind gusts in the strongest cells. An isolated tornado cannot be ruled out as well - especially along a surface boundary that extends across the Thumb area. ...South TX... A moist and moderately unstable air mass is present today across south TX, ahead of a weak front. The coverage of thunderstorms is expected to be quite limited today in this region, but any storm that forms could pose a risk of large hail for a few hours. ..Hart/Lyons.. 04/29/2024Read more
Updated 29 April 2024 | 11:18 am
SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0752 AM CDT Mon Apr 29 2024 Valid 291300Z - 301200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS THROUGH LATE AFTERNOON ACROSS THE LOWER MS VALLEY...SOUTH TX...AND SOUTHEAST LOWER MI... ...SUMMARY... Marginally severe wind gusts and hail will be possible today across south Texas, the lower Mississippi Valley and southeast Lower Michigan. ...Lower MS Valley/Gulf coast today... A midlevel shortwave trough over northwest TX/western OK will progress eastward to the lower MS Valley by early tonight. This wave is preceded by a large MCS now over southern LA and the adjacent northwest Gulf of Mexico. Outflow with this convection will continue moving southeastward through day, with some additional storm development possible into southeast LA/southern MS on the eastern flank of the MCS today. Surface heating in cloud breaks, lingering midlevel lapse rates at or above 7 C/km, and boundary-layer dewpoints of 68-72 F will contribute to moderate buoyancy and the potential for strong updrafts along the leading edge of the MCS. Vertical shear will not be particularly strong, but the stronger storms will be capable of producing isolated downburst wind damage through this afternoon. Farther north, the residual effects of prior and ongoing convection will be reduced lapse rates and low-level moisture, which along with lingering clouds will tend to limit buoyancy. Thunderstorm development will be still be possible this afternoon/evening from AR into western TN/KY along and in advance of a weak surface front and the midlevel trough approaching from OK. However, severe storms are not expected as a result of both weak buoyancy and relatively weak vertical shear. ...South TX this afternoon... A weak front will drift southward into south TX by this afternoon, providing a potential focus for isolated thunderstorm development. Rich moisture, steep midlevel lapse rates and modest deep-layer vertical shear (straight hodographs) could support isolated large hail/wind damage if storms do form. ...Lower MI this afternoon... A midlevel trough will continue northeastward from the upper MS Valley to the upper Great Lakes, while an associated/weak surface cyclone and cold front move across WI/MI this afternoon through tonight. Southeast Lower MI will be located within the warm sector and could have an opportunity for some surface heating/ destabilization just east of the weakening rain band from IN into western Lower MI. MLCAPE up to 500 J/kg, steepening low-level lapse rates and 50 kt midlevel flow support a low-end threat for wind damage this afternoon. ..Thompson/Leitman.. 04/29/2024Read more
Updated 29 April 2024 | 7:56 am