TROPICAL UPDATE: MONDAY, SEPTEMBER 23, 2019

KAREN IS STRUGGLING, AND ITS FUTURE IS A BIT FUZZY. FLORIDA AND THE BAHAMAS WILL HAVE TO WATCH IT. FORECAST CHANGES ARE LIKELY.

KAREN is moving toward Puerto Rico and the Virgin Islands through hostile upper winds, which are trying to tear the system apart. It may weaken in the short term, but the pattern is forecast to be conducive for development when it moves into the Atlantic north of the islands.

Beginning tomorrow, gusty winds and heavy rain will impact Puerto Rico and the Virgin Islands, no matter what condition Karen is in.

After the system moves past Puerto Rico into the Atlantic, the forecast becomes much less certain. Computer forecast models indicate that a strong high-pressure system – the same one that’s bringing very hot weather to the southern U.S. – will block Karen from moving out to sea. Toward the end of the week, the system is forecast to stall north of Puerto Rico and well east of the Bahamas.

The big unknown is, how conducive for strengthening is the weather pattern going to be at that time? And/or is enough of Karen left to strengthen? The computer forecast models generally forecast strengthening – some more than others. In any case, nothing is going to happen quickly. Karen, or whatever is left of it, will be drifting in the Atlantic north of Puerto Rico late in the week.

The blocking high-pressure system might deflect Karen – whether it’s a strong system or a remnant – toward Florida over the weekend. That’s why we will have to pay attention.

Here are the Key Messages on Karen from the National Hurricane Center:

1. Heavy rainfall will continue to affect portions of the southern Windward Islands through tonight.

2. Karen is forecast to approach Puerto Rico, and the U.S. and British Virgin Islands on Tuesday, and a tropical storm warning is in effect. Tropical-storm-force winds, heavy rainfall, and flash flooding are possible on these islands.

TROPICAL STORM JERRY is headed in the general direction of Bermuda. It will pass the island later tomorrow or early Wednesday, but will not be as strong as Humberto was last week.

TROPICAL DEPRESSION THIRTEEN has formed just off the coast of Africa. It is expected to become Tropical Storm Lorenzo soon and strengthen to a hurricane. But the forecast calls for it to move out to sea.

ELSEWHERE, there are no areas of concern developing.