Hurricane Ida made landfall near Port Fourchon, Louisiana at 11:55 p.m. CDT Sunday, with maximum sustained winds of 130 knots (150 mph) and a minimum pressure of 930 mb. Ida was the second-most intense hurricane to ever hit the state of Louisiana by minimum pressure, with only Hurricane Katrina of 2005 having a lower pressure (920 mb). Since that time, land interaction and increasing wind shear has caused Ida to weaken rapidly, and Ida is now down to tropical depression status. In addition to Ida, Tropical Storm Kate has formed over the central tropical Atlantic, but is likely to stay weak and pose no threat to land areas. There is also a tropical wave – Invest 90L – with a high chance of development to become a classic, long-tracked “Cabo Verde hurricane.” Somewhat forgotten in the recent Atlantic hurricane activity was short-lived Tropical Storm Julian, which formed over the central Atlantic yesterday morning and quickly became post-tropical yesterday evening.

As of 4:00 p.m. CDT (5:00 p.m. EDT) Monday, Tropical Depression Ida was centered near 32.6°N 90.3°W, and was moving north-northeastward at about 9 mph. Maximum sustained winds were 30 knots (35 mph), with an estimated minimum pressure of 999 mb. Ida should continue to weaken as it begins to turn more to the northeast and accelerate northeastward, and is expected to become a post-tropical cyclone by around late Wednesday morning. Water levels along the Northern Gulf Coast are receding and should continue to do so tonight. All Hurricane, Tropical Storm, and Storm Surge Warnings have been discontinued. Regardless, Ida’s threat is not over yet, with continued flash flooding likely and elevated river levels for at least another week. An additional 2-4 inches of rainfall is possible over southeastern Louisiana and southern Louisiana, with the National Hurricane Center expecting total storm rain accumulations of around 10 to 18 inches. NHC expects an additional 3-6 inches of rain for coastal Alabama to the western Florida Panhandle, Middle Tennessee Valley, Ohio Valley, and the Central/Southern Appalachians into the Mid-Atlantic. NHC also expects an additional 4-8 inches of rainfall from central Mississippi into western Alabama, and potentially 2-4 inches of rain with isolated higher amounts in southern New England.

As of 5:00 p.m. EDT Monday, Tropical Storm Kate was centered near 22.7°N 50.9°W, and was moving northward at about 10 mph. Maximum sustained winds were 35 knots (40 mph), with an estimated minimum pressure of 1006 mb. Kate is a very disorganized tropical cyclone, with the low-level circulation fully exposed to the west of a disorganized mass of deep convection. Strong northwesterly vertical shear has displaced nearly all of Kate’s deep convection, and this shear has prevented the cyclone from increasing in organization. Although sea surface temperatures are warm (near 28°C/82.4°F) and wind shear is expected to decrease to less than 10 knots in about 36 hours, very dry mid-level air is likely to limit significant strengthening during that time. Some of the model guidance yesterday indicated that Kate could significantly intensify around Day 4-5, but this no longer appears likely due to Kate’s current poor organization, which will limit the cyclone’s ability to be able to persist in the dry conditions in 3-4 days. In about 5 days, Kate or its remnants are expected to be absorbed by an extratropical low over the northern Atlantic south of Canada. Kate is currently no threat to any land areas.

In addition to Ida and Kate, a tropical wave that has just moved off the coast of Africa, designated Invest 90L, has a high chance to develop into the Atlantic’s next tropical cyclone. The NHC gives 90L a 70 percent chance of development within 48 hours, and a 90 percent chance of development within five days. Although the eastern tropical Atlantic has not been very active thus far this season, that is likely to change with 90L. An area of low pressure has already developed, with deep convection already somewhat well-organized. As a result, tropical cyclogenesis is likely to occur quickly, possibly as soon as tomorrow evening. Both the statistical and global model suites are quite aggressive with this system, and it appears poised to develop into a long-tracked “Cabo Verde” type hurricane. Historically, tropical cyclones that form this far east recurve into the open Atlantic without posing any threat to the Caribbean or United States, and it appears likely to happen in that case. That being said, 90L is worth monitoring in case this expectation changes. The next name on the Atlantic naming list is Larry. It is interesting to note that despite this hurricane naming list being used for the 8th time, the name Larry has only been used once before, in 2003.