1/18 – Brittany’s “Approaching Cold Front” Wednesday Night Forecast
An upper low currently is deepening as it crosses the southern portion of the Rocky Mountains. As this upper low moves across the Central Plains today and tonight, a surface low will develop on the leeside of the Rockies and track right along with the upper low. Those features far proximity from the CWA means the strongest dynamics will mostly be north of the local area. Model soundings show low level shear to mostly be supportive of sub-severe with only 0-6km shear in a range that would promote supercell type storms. The other limiting factor is low level instability. Even in northwestern portions of the CWA, surface to 700mb CAPE is so minimal that it`ll be hard for robust updrafts to even develop. South of a BTR to Tylertown line just looks even less conducive. There will be “some” elevated instability but even that doesn`t look impressive. Therefore, while there`s a Marginal Risk for severe thunderstorms, it`ll be hard pressed for anything severe to develop as a line of thunderstorms moves through Wednesday night. CAMs are quite similar in timing with storms reaching western portions of the CWA just after 00z and reaching Jackson County MS close to sunrise Thursday. It should be noted that CAMs also show a steady weakening after midnight, which lines up will with decreasing instability and shear with time.