2PM Day 1 Convective Outlook CORR 1 for Tuesday, March 3. THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS THE SOUTHERN/CENTRAL PLAINS INTO MISSOURI AND WESTERN ILLINOIS
CORRECTED FOR TESTING THE CORRECTION PROCESS
SUMMARY
Isolated severe hail may occur this evening into the overnight hours across parts of the southern/central Plains into Missouri and western Illinois.
20z Update
The Marginal Risk continues across parts of the southern/central Plains into Missouri and western Illinois. Moisture continues northward, observed in visible satellite and 60 F dew points increasing from the south into southern Kansas. Thunderstorm development is still expected to be delayed into the evening as modest capping remains in place. Some conditional risk for large hail (some up to 1.5-2" in diameter) will be possible, mainly across northwest Oklahoma into southern Kansas. In this region, a favorable overlap of MLCAPE around 1000-1500 J/kg will overlap with steep mid-level lapse rates and deep layer shear near the frontal boundary.
Southern/Central Plains into Missouri and Western Illinois
Water-vapor imagery this morning shows a mid-level shortwave trough over the central Rockies and this feature will move into the central High Plains late tonight. A frontal zone this morning is draped from near the Raton Mesa into the TX Panhandle extends east-northeastward across northern OK into the Ozarks. A weak surface low over northeast NM and the OK/TX Panhandles this morning will gradually develop towards northwest TX by this evening. Southerly low-level flow will maintain a moist fetch into OK today and into the Ozarks and parts of the mid MS Valley. A dryline is forecast to mix eastward across the southern High Plains by late this afternoon, intersecting the surface front in the northwest TX/southwest OK vicinity.
Convection will likely be inhibited during the day across much of the MRGL Risk owing to both capping and weak mid-level shortwave ridging. The strongest heating and low-level convergence is forecast across parts of northwest TX/southwest OK where convective inhibition will become weakened by late afternoon. Have adjusted severe hail probabilities farther south into parts of northwest TX to account for the potential for a supercell or two this evening into the overnight hours. As large-scale forcing for ascent continues to strengthen through the evening into the overnight, expected widely scattered thunderstorms to eventually develop near the frontal zone (perhaps favoring a northwest OK/southern KS corridor). Large hail will be the hazard with the stronger storms. Around 1000-1500 J/kg of MUCAPE, steepened mid-level lapse rates, and strong effective bulk shear suggest that some of these cells may pose a threat for isolated severe hail as they spread from OK/KS into MO and western IL through early Wednesday morning.