SPC Mesoscale Discussion: Severe Potential… Watch Possible

SUMMARY…Risk for surface-based/severe storms — including some tornado potential — will continue to spread gradually northward into coastal portions of the central Gulf Coast region. A tornado watch may eventually be required.

DISCUSSION…Latest surface analysis depicts a weak low near PSX (Palacios TX), along a wavy surface baroclinic zone that is now returning northward as a warm front across the northern Gulf. The front remains just off the Louisiana coast in all areas, with the exception of the southern tip of Plaquemines Parish at the mouth of the Mississippi. A sharp thermal/moisture gradient exists from the coastal regions to the northern Gulf, with east-northeast surface winds maintaining 50s F temperatures/dewpoints inland, and 70s observed just offshore. While the aforementioned east to northeast surface winds, and inland precipitation, will keep northward advance of the warm front restrained, the slow/steady advance of Gulf air will continue, as the upper trough advancing gradually eastward permits modest deepening/northeastward movement of the weak Texas coast frontal low. Strongly veering/increasing flow with height is observed via WSR-88D VWPs inland/north of the front, within the zone of low-level warm advection. Large/looping hodographs are thus observed, with 0-1KM shear quite favorable for low-level rotation. Though low-level shear is obviously less pronounced within the warm sector, sustained/rotating storms developing over the Gulf and moving northward across the boundary may be capable of producing inland tornadoes as the morning progresses. We will continue to monitor evolution of both the warm front, and of the offshore storms, with an eye toward possible tornado watch issuance over the next couple of hours.

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