
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0705 AM CDT Wed Apr 29 2026 Valid 291300Z - 301200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM PARTS OF TEXAS INTO THE LOWER MISSISSIPPI VALLEY AND THE CENTRAL GULF COAST... ...SUMMARY... Strong to severe thunderstorms should impact a corridor from parts of Texas to the Gulf Coast states today. Scattered damaging winds and large hail are the main threats, with isolated very large hail possible across portions of Texas. ...Texas into the Lower Mississippi Valley/Southeast... A broad zone of enhanced westerly mid-level flow will persist today over much of the southern Plains into the lower MS Valley and Southeast. Multiple weak embedded perturbations aloft moving from northern Mexico across the southern Plains should encourage isolated to scattered thunderstorms to develop through the day along/near a surface front draped from west-central TX to southern AR. A rather moist low-level airmass remains in place along/south of this boundary, with surface dewpoints generally in the low to mid 70s. Steep mid-level lapse rates atop this moisture are supporting up to 2000-4000 J/kg of MUCAPE across TX, with somewhat lesser values into the lower MS Valley. Current expectations are for a gradual increase in convective coverage and intensity this morning through the afternoon as the weak mid-level shortwave impulses develop eastward across the warm sector, with multiple zones of initiation possible along/near the front. Regardless of where thunderstorms form, the moderate to very strong instability and elongated/nearly straight hodographs at mid/upper levels should support a threat for large hail with any persistent supercells. This hail threat should be greater across TX (with isolated 2+ inch diameter hailstones possible here), but isolated severe hail may occur as far east as the central/southern AL vicinity. A tendency for thunderstorms to cluster and pose a greater damaging wind threat may focus across parts of the lower MS Valley, generally along/southwest of ongoing convection occurring this morning in east-central MS to northern/central AL. Given increased confidence in convection initiating and being sustained, a Slight Risk for the hail/wind threat has been introduced from parts of TX to southern AL with this update. ...Mid-Atlantic/North Carolina... Within large-scale upper troughing over the Great Lakes/Midwest, an embedded mid-level shortwave trough will move northeastward across the Mid-Atlantic this afternoon/evening in tandem with an eastward-moving surface cold front. Only modest boundary layer moisture is present across the region, with surface dewpoints generally in the 50s. Filtered diurnal heating will result in generally 250-750 J/kg MLCAPE (locally greater possible in NC). Despite this weak instability, strong deep-layer shear should aid in transient organization of the more robust cores that can form. An isolated threat for hail and damaging winds remains apparent. 0-1 km SRH around 100-150 m2/s2 in proximity to a weak surface low could also support a brief tornado. ..Gleason/Jewell.. 04/29/2026Read more

Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0358 AM CDT Wed Apr 29 2026 Valid 021200Z - 071200Z ...DISCUSSION... Latest medium-range guidance, in particular the ECENS and GEFS, generally maintains forecast trends of prior runs concerning the evolution of the large-scale features within the prevailing split flow through this weekend into early next week. It appears that at least a transient blocking high may evolve within amplified ridging offshore of the British Columbia and adjacent Pacific Northwest coast. To its south-southeast a notable mid-level low is forecast to evolve within initial troughing slowly digging toward the U.S. Pacific coast, with the low bottoming out offshore of the central/ southern California coast by early next week. Downstream, it appears that a broad area of lower mid-level heights will be maintained, with lowest heights perhaps reforming west-northwestward from southwestern Quebec toward southern Hudson Bay/northwestern Ontario, contributing to the maintenance of a confluent regime across and east of the Rockies. Shorter wavelength developments within this pattern remain more uncertain, particularly by the early to middle portion of next week, when it appears that the offshore low will begin to progress inland across California and the southern Sierra Nevada. Depending on the timing of the inland progressing mid-level cold core with respect to diurnal heating, this could be accompanied by relatively minor severe weather potential across parts of the San Joaquin Valley next Monday or Tuesday. Downstream, southerly moist return flow into at least the southern through central Great Plains, associated with deepening lee surface troughing, may contribute to destabilization beneath building mid-level ridging across and east of the southern Rockies. This might be accompanied by increasing potential for at least widely scattered strong to severe thunderstorm development on Tuesday. Guidance suggests potential for more widespread organized severe thunderstorm development could increase by Wednesday, but much will depend on short wave developments which become rather uncertain by this time.Read more