Currently in the Atlantic - November 1st, 2022

The weather, currently.

Lisa - dry air on west side

Tropical Storm Lisa clearly has a complete circulation and has strengthened since yesterday. There are thunderstorms near the center, but it is still "out of balance." The west side of the storm is much clearer than the east. It appears to be to be due more to the dry air than wind shear. Look at the water vapor satellite below:

Dry air in yellow and orange west of Lisa

The driest air is more to the northwest of the storm than the area south of due west. This is critical to the future intensity of Lisa. So, watch the NHC advisories for the exact movement. Direct west is 270 degrees. Every number higher than 270 moves Lisa into drier air. And every number lower than 270 keeps Lisa in enough moist air to potentially intensify. Below are the computer model tracks and then intensity forecasts:

Complete agreement on direct hit to Belize
Some intensity disagreement, but....

The future track is surely westward, but a little north of due west. As we've seen, even slight differences in the exact track can have a big impact on future intensity. Some models suggest Lisa may become a hurricane Wednesday before landfall in Belize, although the majority suggest it stays a tropical storm. But if it happens to move straight west, it will hit the northern part of Honduras, causing it to weaken.

Here is what to watch for. First, the current position and movement (using 5pm Monday as an example):

TROPICAL STORM CENTER LOCATED NEAR 15.5N  78.4W

PRESENT MOVEMENT TOWARD THE WEST OR 270 DEGREES AT  12 KT

OK, that's straight west. Now, look at the latitude and longitude changes. In 24 hours:

FORECAST VALID 01/1800Z 16.2N  82.8W. This is a movement northward 0.7 degrees, while the west movement is 4.4 degrees. So, it will have moved slightly north of due west. It is the first number (latitude) that is most important here. Now, another 24 hours later:

FORECAST VALID 02/1800Z 17.0N  87.6W. That's another 0.8 degrees north of due west. At that point, Lisa is predicted by NHC to become a hurricane. Just far enough north to not make landfall in Honduras, and not far enough north to hit the dry air.

You can see how close a call it is regarding intensity. Just a few miles can make a significant difference in this case. Then, Lisa is expected to slow down after landfall in Belize, which will add to the rain/flood threat. More clues coming...

Glenn "Hurricane" Schwartz — thehurricaneschwartz@gmail.com

What you need to know, currently.

Tropical storm Lisa formed in the central Caribbean Sea Monday morning, becoming the 12th named storm of the 2022 Atlantic hurricane season. It will move towards part of Central America later this week, possibly turning into a hurricane.

As of 11 a.m. on Monday, the storm was around 175 miles south of Jamaica and moving west at 14 miles per hour with maximum winds of 40 mph, according to the National Hurricane Center in Miami.

Lisa is expected to continue westward, passing near or just north of Honduras’ northern coast late Tuesday through Wednesday. Lisa will then scrape into Belize Wednesday night, then into Guatemala Thursday, before hitting southeast Mexico later Thursday or early Friday.

A tropical storm watch is in effect for Jamaica, but was cancelled in Grand Cayman. Tropical storm conditions are still possible throughout Monday.

“The coast of Central America, especially near Belize and the Yucatán Peninsula of Mexico, should monitor the progress of the system,” the National Weather Service said.

The current forecast puts Lisa up to a Category 1 hurricane by the time it makes landfall in Belize Wednesday night.

Storm surge flooding and heavy winds are possible where Lisa makes landfall. Heavy rain is also a threat with Lisa in Central America, including Nicaragua, Honduras, Belize, Guatemala and southeast Mexico. These conditions could trigger flash flooding and landslides in hilly areas as well.

The Atlantic hurricane season, which runs from June through November, had a pretty quiet start with only three named storms before Sept. 1 and none during August. This hasn’t happened since 1997. By the end of September, though, Hurricane Ian devastated the coast of Florida as a Category 4 hurricane.

Last year, there were 21 named storms, after a record-breaking 30 in 2020.

Of course, this can all be linked to climate change. A warming planet creates conditions that are suitable for stronger, more frequent hurricanes. Hurricanes are also becoming wetter, as more water vapour forms in warmer atmospheres. This leads to much more rain than there would be without human-induced climate change. Rising sea levels also contribute to higher storm surge.

For more information on hurricanes, read our Currently Explainer here.

And subscribe to our Currently in the Atlantic newsletter for daily updates on this hurricane season.

—Aarohi Sheth