Hurricane Carlos becomes tropical storm, to regain hurricane status by Tuesday

Hurricane Carlos, as hurricanes do, is behaving unpredictably.

The storm is still a few days from Central Pacific waters, and in recent hours has weakened. Weather forecasters aren't sure why.

(Image: Carlos is the cyclone spinning on the left, while an unnamed area of thunderstorms to the right has a 30 to 50 percent chance of turning into a cyclone by Tuesday, forecasters say. Credit: NOAA.)

It has actually dropped to tropical storm force, (it's being called Tropical Storm Carlos again) but meteorologists are forecasting it to strengthen to hurricane force again by Tuesday, and then begin another weakening phase.

Meanwhile, the hurricane continues to move toward Hawai'i at a rate that carries it 240 miles a day. At this writing its center is a little more than 2,000 miles from the Big Island, and well south. At 11 a.m. Hawaiian time, it was 10.3 degrees north latitude and 121.3 west longitude. It is heading west at 9 knots. That's a little slower than yesterday.

The 11 a.m. Carlos advisory is here: http://www.nhc.noaa.gov/text/refresh/MIATCPEP4+shtml/DDHHMM.shtml

In their official estimates, National Weather Service officials admit to being a little puzzled by the appearent pulsing behavior of the hurricane's strength: weak-strong-weak-strong.

“It still is a bit of a mystery why the cyclone weakened as much as it has today,” the service said. Computer models indicate that it should bulk up again, in part because of warmer water where it's traveling.

“There does exist a two to three day window for Carlos to restrengthen as it traverses over warm waters and through an environment of low vertical shear and moist unstable air,” the experts say.

After that—by Friday or Saturday of this week, it is forecast to sail into cooler waters again, as well as facing a region with contrary upper winds that could weaken the storm.

There are lots of options for this storm: It could dissipate entirely, it could gain strength and keep going, it could keep its westerly course and pass well away from the Islands, it could dissipate but bring the Islands lots of rain in a little more than a week. Shucks, it could spin around and head back for Mexico. It's happened before.

Meanwhile, for those of us fascinated by weather, a correspondent alerted us that there's another feature right behind Carlos.

About halfway between Carlos and the Central American coast is a very large area of rain and thunderstorms. The weather service is predicting there's a 30 to 50 percent chance of this system turning into a cyclone within two days.

“Conditions appear favorable for the gradual development of this system,” forecasters say.

© Jan TenBruggencate 2009