Heavy Rain Potential Thursday-Saturday AM, Where Does Boundary Set UP?

Typically, after a long dry spell, Mother Nature reverses to a much wetter pattern, often causing flooding.  That appears to be shaping up for later this week as the upper-level flow becomes zonal (west to east), resulting in a cold frontal boundary stalling somewhere along the Gulf Coast.  Weak upper disturbances will bring several rounds of rainfall, and IF the band of rain aligns itself with the upper flow, training of cells could create a band of excessive rainfall.  Let's set the stage with what is happening now. An "atmospheric river" of Pacific moisture is streaking towards Louisiana.

Currently, that boundary extends from east Texas across northern Louisiana into central Mississippi. WPC's 7-day rain total map highlights a band stretching just north of us.

Clearly, RIGHT NOW, the model has the band of heaviest rainfall well north of Lake Pontchartrain.  IF that proves to be reality, we'll just have to deal with some spotty storms the next several days.  BUT, what if the band sags farther to the south?  The white colors indicate 5-10"+ totals over several days. We need to pay attention to where this boundary sets up.  I liked this graphic Hannah Gard used on FOX 8 this morning.

She indicated there will be several rounds of heavy rains with each upper disturbance.  That would allow the pumps to keep up.  Bottom line, we have the POTENTIAL for 2-4"+ of rain on the South Shore between Thursday and Friday, with higher amounts to the north.  Here's the boundary right now.

It is cooler behind the front, but the air is much drier (lower dew points).  That good feel will return for Saturday PM into next week.

Obviously, the red areas (First Alert) should be on Thursday, Friday & Saturday.  I just grabbed these graphics from the FOX 8 weather page, and they must be in the middle of updating it. Saturday PM & Sunday look great for JazzFest.  So let's pay attention to the radar over the next several days to see if this boundary of heavy rainfall reaches the South Shore. It's a given that it will reach most of the North Shore.  Finally, I wish Hannah Gard great success as she moves to Austin, Texas, for the next several years.  Her replacement (Grace Williams) will arrive next month.  Stay tuned!