About Jeff Masters
By: Dr. Jeff Masters , 1:50 PM GMT on September 14, 2006
It's a typically active mid-September day in the Atlantic, with the first major hurricane of the year, Gordon, spinning out to sea, and a new tropical storm to watch, Helene. Neither of these storms are likely to affect land, and the long range 2-week GFS model forecast offers no hint of any future threats coming in the Atlantic. With hurricane season now more than half over, the seemingly radical notion that the worst storm of the season will end up being Ernesto is not so far-fetched. Still, there is another full month of peak hurricane season to go, and we still need to keep an eye on Helene, which could cause trouble.
The remains of Hurricane Florence gave Newfoundland a pounding yesterday, bringing hurricane force winds and 30-foot seas to the coast. One house was reported destroyed on an island off the coast, and there were scattered reports of power outages and flooding. The remains of Florence will continue across the Atlantic, and likely bring heavy rain and 40 mph wind gusts to Ireland on Sunday.
Gordon headed out to sea
Hurricane Gordon intensified into the first major hurricane of the season last night, but appears to be starting a slow decline in strength. Strong upper-level winds from the west are creating about 15 knots of wind shear over the storm, and helping stretch it into an east-west oriented oval shape. Wind shear over Gordon is expected to increase and the waters underneath it cool over the next few days. Gordon is headed northward out to sea, and is not a threat to land.
Figure 1. Latest satellite image of Gordon, updated every half hour.
Tropical Depression Eight got its act together enough last night to barely qualify as the eighth named storm of the season, Helene. Helene is very disorganized and has a large sloppy circulation center. A QuikSCAT satellite pass from this morning shows this broad center nicely, and reveals only a few patches of winds over 40 mph. As we saw with Florence, it can take many days for a weak tropical storm with a large circulation center to organize into a hurricane. Still, the waters under Helene are a warm 27-28C, the shear is a low 5-10 knots, and these favorable conditions for intensification are expected to persist for several days. Helene should be able to intensify into a hurricane by 3-4 days from now, and possibly into a major hurricane thereafter. Some dry air to its north and west may interfere with this intensification.
The computer track models have a wide spread in the track for Helene, but all of them take the storm north of the Lesser Antilles. While a long-range threat to Bermuda and the U.S. East Coast is still a possibility, the odds of this happening are low. History shows that the large majority of tropical storms that form in this part of the Atlantic end up recurving harmlessly out to sea. With the active jet stream pattern we've seen since early June expected to continue for at least the next two weeks, I expect that Helene will end up recurving out to sea east of Bermuda.
More trouble for Mexico
Tropical Storm Lane formed off the Pacific coast of Mexico yesterday, and this storm has the potential to be the most trouble of any storm discussed so far. Lane is expected to track parallel to the coast and threaten Baja, similar to what Hurricane John did earlier this month. Lane is over warm waters and under light shear, and and has the potential to become a hurricane by Friday. Lane probably does not have time to intensify into a major hurricane, but a Category 2 hurricane would not be a surprise.
The entire coast of Mexico affected by John is also at risk from Lane. The storm could move ashore on the mainland Mexico coast south of Puerto Vallarta, like the GFDL model is forecasting. The GFDL had the best performance of any of the computer models for John, so residents along the mainland Mexican coast should prepare for a possible direct hit by a Category 1 hurricane on Friday.
Moisture from Lane could potentially reach southern California and Arizona by Wednesday and cause flooding concerns there.
The rest of the tropical Atlantic
Thunderstorm activity is increasing today along a cold front stretching from Cape Hatteras, NC, to the waters east of Florida. This area will have to be watched the next two days for development. Shower activity associated with a tropical wave passing through Puerto Rico and the surrounding region have diminished, and development is unlikely here.
Finally, I had to link this photo of a fire tornado taken by wunderphotographer Photo5150. Some fires are able to create such a strong updraft with their extreme heat that the air rushing in at the surface to replace the air lifted creates a fire tornado. This is definitely the most awesome photo of a fire tornado I've ever seen!
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