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!

Significant Rains Coming To Louisiana/Mississippi, JazzFest Timing Could Be Perfect

  We all know how dry it's been this Spring across the Southeast.  That is about to end as a cold front is likely to stall, and coupled with several upper disturbances, produce a band of heavy rainfall.  Where that band set up is not a lock, but WPC's 7 Day rainfall totals are centered just to our north.

The band from east Texas into Alabama might see 5-7" over several days.  SPC's severe outlook quickly weakens any threat as the cold front nears.  Today is an active day to our north.(top graphic)

SPC quickly weakens the threat for Wednesday (Bottom view) Radar is showing some very strong storms moving west to east at 4 PM.

These storms will stay well north today, but the boundary should sink farther to the south for Wednesday.  The 1st 90 degree day (That all channels have been hyping) will have to wait as the upper ridge over Mexico has flattened and the frontal boundary should produce more clouds.

Where the upper flow splits,(orange circle), that is where the severe storms are developing.

You don't see any 90+ to our west, but you do see dew points to 70+.  That means there is plenty of low level moisture that could produce some pop up showers during daytime heating.  The timing of the front appears to give the greatest shower chances after 4 PM Friday through 10 AM on Saturday.

If the timing works out, Saturday PM & Sunday should be delightful.  I believe the FOX 8 extended is too aggressive with the cooler temps.    The South Shore  can no longer see nights in the 40s.  Still, any cool down will be welcomed.  We really could use the rain.  Too bad it's coming for part of this weekend.  Stay tuned!