Tropical Storm Lala Forming Southeast of Hawaii and Watching for Development in the Atlantic

The disturbance about 700 miles southeast of Hawaii Island is organizing. The National Hurricane Center is likely to designate it Tropical Storm Lala today. Winds have already been measured at 40 mph, so it will skip the tropical depression stage.

Tropical Storm or Hurricane Watches will be issued for some of the islands soon. If the system takes the path that's forecast, watches and warnings will spread across all the Hawaiian Islands over the next couple of days.

The system is forecast to intensify into a strong tropical storm or Category 1 hurricane as it approaches the vicinity of the islands. Weather should start deteriorating on the east coast of the Big Island late Friday.

On the current schedule, likely-Tropical Storm or Hurricane Lala will impact all of the Hawaiian Islands to some degree over the weekend. The weather should return to normal on Monday, as Lala exits to the west.

As with all disorganized tropical systems, the exact track and intensity are unknowable this far in advance, and the details of the forecast are likely to change.

According to the strong consensus of the various computer forecast models, the center of Lala will track just south of the islands. Since the worst weather with the storm is likely to be north of the center, the odds of impacts on land are high.

The atmospheric environment is not conducive to Lala blowing up into a Category 3 or 4 hurricane. But a strong tropical storm will produce hurricane-force winds against the higher elevations, and heavy rain that falls on the windward slopes will have to come down the hills. This means flooding is a real possibility.

Plus, the tides are already running high, so the huge waves generated by Lala are likely to flood some low-lying coastal areas.

There's no way to know at this point exactly where the strongest and most moist onshore winds will impact the islands, although windward and mauka (inland up the mountain) areas are likely to feel the brunt of the storm. This means that everybody in Hawaii needs to be ready to ride out the storm in a safe place this weekend.

Stay informed and follow the direction of the National Weather Service in Honolulu, the Hawaii Emergency Management Agency, and local officials. They will be working hard to keep everybody safe.

IN THE ATLANTIC

Tropical Storm Cristobal has come and mostly gone in the open North Atlantic. Its main function was to use up the C name on the list. Every year has that kind of quick-hitter storm.

In the tropical Atlantic, we're still following the two disturbances. The National Hurricane Center has designated the left-hand one Invest 92L. The one closer to Africa is tagged Invest 94L. An invest is just a disturbance that the NHC is running specialized computer models on, which provide some detailed analysis. The systems are still disorganized disturbances.

Invest 92L has a solid circulation, but so much dry air has wrapped into it that it can't produce organized thunderstorms. The Saharan dust just to the north is going to make it difficult or impossible for this system to gain much strength, unless it can find, even briefly, a pocket of moist air. As it moves into the Caribbean this weekend, the upper-level winds will become prohibitive of further development and will likely tear apart the system.

Hopefully enough moisture will survive to reach the Caribbean islands that have been suffering a significant drought.

The system behind it, Invest 94L, which the National Hurricane Center is giving a medium chance of developing into at least a tropical depression, is embedded in an envelope of moisture, and it's on a slightly more southern track – meaning it's a little farther from the dust. It will arrive in the vicinity of the northeast Caribbean around Tuesday. The consensus of the various computer forecasts is that it's likely to turn to the north near or over the islands.

The atmospheric environment is so hostile over the Caribbean and the nearby waters that it is unlikely either system will be a significant threat to the islands. Obviously, they bear watching to be sure nothing unexpected happens, but hopefully one or both will enhance rainfall where it's desperately needed.

Robust thunderstorm complexes are building over Africa so we can expect more disturbances over the tropical Atlantic as we move toward the typically busy part of the hurricane season.

If the Saharan dust behaves as it normally does, it will slowly wane through August, but the hostile winds, which are driven by El Niño, will continue and likely increase through the hurricane season.