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Posted at 11:15 AM ET, 08/31/2011

Katia now a hurricane; Atlantic hurricane season still to peak


Water vapor image showing tropical storm Katia in central Atlantic (NOAA)

UPDATE, 11:37 p.m.: Katia is now a hurricane, the Associated Press reports, becoming the second named hurricane of the season in the Atlantic Ocean.

Earlier:

Tropical storm Katia, spinning away in the central Atlantic, is quickly closing in on hurricane intensity. And more ominously, the atmosphere across much of the rest of the tropics shows signs of becoming even more fertile.

In the most recent update from the National Hurricane Center (NHC), Katia, was positioned 1,100 miles west of the southernmost Cape Verde Islands. It is expected to continue moving quickly west-northwestward at around 20 mph for the next several days through the central Atlantic.

Intensity forecast

Its maximum sustained winds are around 65 mph, 9 mph shy of hurricane intensity, and NHC expects the storm to intensify to category 3 hurricane status in about three days (and several models eventually strengthen Katia to category 4). But like so many systems in recent times, Katia will have to fight off the potentially disruptive effects of a large area of dry air that currently resides across much of the tropical Atlantic ahead of its projected path (the dark and bronze areas in the water vapor picture above).

We’ll see in the coming days how effectively (or if) Katia can maintain a core of deep convection (tall thunderstorms) near the circulation center in the midst of the apparently dry surroundings. On the flip side, the nearby water is warm enough to support further development and the shear, for now, doesn’t seem to be a problem.

Track forecast


Track models tend to steer Katia away from U.S. East Coast ( South Florida Water Management District )
Where it’ll go, nobody knows. But there are signs from the global weather models and their ensemble systems that there will be multiple opportunities for Katia to recurve out to sea long before the storm approaches North America.

To even begin worrying about a potential East Coast threat from Katia is at this stage way too premature. No one should consider altering any travel plans based on this storm right now.

Gulf of Mexico development?

Closer to home, over the western Caribbean and Gulf of Mexico, the weather appears a bit agitated.

Transient clusters of storms have well populated the local atmosphere for the last couple of days. In addition, a broad cyclonic (counter-clockwise) low-level flow and relatively low sea-level pressures currently occupy the region.


Though the air aloft is very dry for now across the northern Gulf of Mexico, it will probably moisten up at least a little in the next couple of days as southerly winds transport more humid air poleward from tropical latitudes. With these favorable conditions in place, it’s not surprising that many of the weather models have consistently hinted at some tropical development in the Gulf as we head toward the weekend. Though nothing is imminent, the fact remains that there’s no realistic way for a tropical cyclone to avoid crossing land once it’s in the Gulf. That’s really the only part of this that bothers me right now.

If a tropical depression forms, it would be the 13th of 2011 (TD13). And if it becomes a tropical storm or hurricane, its name would be Lee. We will be watching this for you.

Hurricane season nearing peak
The climatological peak of hurricane season is around September 10 - about two weeks away. (National Hurricane Center)

In may not seem like it, but we have a long way to go before the 2011 Atlantic hurricane season shuts down. In fact, the climatological peak of the season is still nearly 2 weeks away (image courtesy of NHC).

As suggested by the historical records, tropical cyclones are almost equally capable of forming anywhere across the Atlantic, Caribbean Sea, and the Gulf of Mexico in the first half of September. That’s not particularly comforting given what we’ve been through so far.

By  |  11:15 AM ET, 08/31/2011

Categories:  Tropical Weather, Latest

 
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