3/24 – Brittany’s “Cold Front Approaching” Friday Evening Forecast
Scattered showers have developed generally along and north of the I10/12 corridor over the last few hours. The special 18z sounding shows plenty of instability. However, a very stout EML was present over the region. This activity looks to remain rather low topped over the next couple of hours. As better heightfalls spread into the region, the EML may erode just enough to allow for a bit better vertical growth across the northern tier, but with the thickening CU field out ahead there are more questions regarding where the best instability will reside. Regardless, even with a more modest ascent, a stronger LLJ will begin to migrate into the region from the west enhancing low level wind shear, which will need to be watched…especially the SW MS Counties and Florida Parishes. Overall, message remains the same with the best potential for convection residing along and north of I10/12 corridor with the main focus being SW MS.
The front will begin to become parallel to the upper mean southwesterly flow overnight. Along and ahead of the front, moisture pooling will allow for the formation of low stratusagain with perhaps some limited visibilities/patchy fog. This front, although slow moving will eventually slide just south of the region over the Gulf leading to a mostly dry Saturday. Skies look to clear as surface winds run parallel to the frontal boundary limiting much of an isentropic ascent issues…at least until late in the short term period as the front lifts northward back toward our region as a warm front. Expect clouds to be on the increase as the low level flow transitions back to an onshore flow.
Stalled frontal boundary in the area is a driver of rain Sunday through early Tuesday before being pushed eastward by a weak upper level ridge. Placement of the boundary is still a bit uncertain, but close enough that it could influence some severe weather. SPC has our northern half, basically north of I10/12, in a Marginal Risk and southern half categorical for Sunday mainly in the afternoon and evening. We are also under a WPC Marginal Risk of Excessive Rainfall for the Sunday through Tuesday period.