Sunday, August 29, 2021

Hurricane Ida, Tropical Storm Julian, and TD 10: 29 August, Update A

Oh deary me! Ida continued to intensify even after crossing the Loop Current Eddy and has now, finally, made landfall as a strong cat 4 storm with estimated winds of 150mph and a very low central pressure of 933mb (Cat 4 range: 130-156mph), somewhat more robust than all the projections. 

She is currently inland at 29.5N, 90.6W, heading NW at 10mph and winds have decreased to 130mph (central pressure is now 938mb). Landfall was around 11am this morning, in southwestern Louisiana, west of New Orleans - in an area which has a lot of low-lying swampland and is not as densely populated as other parts of that coastline:

She had a lot of convection - rain, thunderstorms - and a clear eye which was about 15 nautical miles in diameter (just over 17 miles):

There isn't any large decrease in appearance or circulation (at all levels of the troposphere) since landfall, even though they have lowered her winds. She still has a very solid eye. The slow change is because of those swampy regions she is going over - essentially it's a continuation of the ocean. 

The issue is the storm surge and flooding. Since Katrina, billions of dollars have been put into the levee system around New Orleans, so they should hold up. However, it will take some time for the Lake to drain out so even though the storm has made landfall, there is still a strain. There are parts of the coastline which have seen over 7 ft of storm surge. As I said yesterday, those on the east side of the eye will experience greater surge because water is being pushed on shore, whereas those on the west side will experience less. Here are some storm surge data charts from...

Shell Beach, LA (east side of eye) - water was 7.55ft above normal: 

New Canal Street Station, LA - New Orleans (east side of eye) - water is 3.16ft above normal: 

Grand Isle, LA (nearest station to eye of storm) but still on the east where water was 4.77ft above normal:

Bay Waveland Yacht Club, MS (east side of eye) - water was 6ft above normal:

And from Amerada Pass, LA (west side of eye) - where water was actually 0.36ft below normal:

The news is still emerging of course but we already know that power is out (and the utilities from many states are already ready to go in to help out - thank you!), some damage to buildings, trees etc. The full impact will emerge in a day or two though. 

She is projected to continue heading inland and then turn to the northeast. She has got a lot of rain, so again, if you are in the path inland be prepared for potential flooding - move out of flood zones. 

Tropical Storm Julian 

This was yesterday's TD 11, which did turn out to be a little better developed than TD10. He is a mid-sized TS with winds of 60mph, central pressure 995mb. He does have some convection, as you can see in the northern edge of this satellite image: 

He is currently at 36.7N, 44.6W, heading NE at 24mph. He is expected to continue moving to the northeast over the next few days as a TS:

He will not survive that far north as 'Tropical' Storm but will morph into a Post-Tropical Storm instead (the NHC expect this to take place tomorrow). 

Tropical Depression 10

She is still struggling to develop. She's at 19.7N, 50.4W, heading N at 12mph. She doesn't have a lot of convection, as you can see in the image above. Winds are estimated to be 35mph, central pressure is 1008mb. I'll keep an eye on her. 

That's all for today. Hoping all my friends and wonderful readers are safe post-Ida! 

Toodle pip,


Blogs archived at

Twitter @JyovianStorm



These remarks are just what I think/see regarding tropical storms - not the opinion of any organization I represent. If you are making an evacuation decision, please heed your local emergency management and the National Hurricane Center's official forecast and local weather service announcements. This is not an official forecast. If I "run away, run away" (Monty Python), I'll let you know.

No comments: