New tropical storm forms in east Atlantic – has tough path ahead

Newly formed tropical storm Grace just to the southwest of the Cape Verde Islands

Newly formed tropical storm Grace just to the southwest of the Cape Verde Islands

The NHC has begun issuing advisories on tropical storm Grace in the far eastern Atlantic. Top winds are 40 mph and it is moving westward over open water.

The forecast calls for modest strengthening despite the fact that the track takes Grace over fairly warm sea surface temperatures. It seems the once again, strong upper level winds coming in the opposite direction could inhibit development if not halt it completely. For the time being, Grace has a chance to strengthen some and it should be noted that some intensity models do make it a hurricane.

Fortunately, the storm is far out in the open Atlantic and there is plenty of time to monitor its progress over the coming days. It will have to battle increasingly stronger upper level winds and, as I mentioned above, those winds may end up causing the storm to dissipate, we will just have to wait and see.

I find it interesting that Grace makes it four storms in a row to develop in the MDR or Main Development Region over past few weeks. This part of the Atlantic, also known as “the deep tropics”, was supposed to be very hostile this hurricane season. Granted, Danny was the only hurricane to really take off, so to speak, but even Fred a few days ago, reaching hurricane intensity just off of Africa, was quite interesting considering the El Nino season we are in. If Grace becomes a hurricane, it will add to the seasonal ACE count which is currently at ~22 and slowly climbing. The ACE index measures the energy output by tropical cyclones each season and is a better indication of the quality of each storm, not the total amount that formed. Most predictions for this season are around 40 ACE points, we are more than half way there.

Elsewhere, Fred is hanging on as a tropical depression, fighting off periodic bouts of strong upper level winds. Once in a while, those winds relax just enough to deep convection to fire up, making Fred a tropical storm once again. Right now, it’s currently on the losing end of the shear duel. I suspect that within a the next 12 hours, Fred will make another comeback and be designated as a tropical storm yet again. Eventually, Fred will be kicked out in to the westerly wind flow of the Atlantic and whisked away.

The east Pacific has an area of interest, 98-E, well to the south of Mexico, that bears watching. It will slowly consolidate and become a tropical storm over the coming days but should remain well to the west of the Baja and vicinity.

I’ll have more on Grace and the rest of the goings on in the tropics tomorrow.

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After Fred, probably going to be quiet for a little while

Fred was an amazing event- bringing hurricane conditions to a small portion of the Cape Verde Islands yesterday; something not seen in well over 100 years in that region.

Now Fred is weakening as it encounters cooler water and more stable environment overall. The short-lived hurricane added a few ACE points to the season total which is now near 20 for those keeping score. ACE is the seasonal accumulation of actual energy that is output by tropical storms and hurricanes. Normally we see an ACE “score” of around 104 – most predicted 40 or less for this season. We are half way there and it’s only September 1.

Wind shear map from Univ of Wisconsin showing very strong winds (blue-ish color) blasting through the tropics

Wind shear map from Univ of Wisconsin showing very strong winds (blue-ish color) blasting through the tropics

So what’s happening now that Fred is on the way out? In short, not much. Take a look at the upper level winds on the graphic. I have highlighted the strongest band of upper level winds which are literally tearing across the deep tropics right now. We are talking about several thousand miles of ocean and the atmosphere above it that is essentially shut down from a tropical development stand point. Any westward moving tropical wave will be met with strong eastward moving wind that will literally tear the system apart.

There are some signs that this could change in the coming week to ten days but don’t look for anything drastic, maybe a slight relaxation of the shear. This would come as a more favorable MJO or Madden-Julion Oscillation migrates through the Western Hemisphere as indicated by the GFS and the ECMWF models. However, it doesn’t look to be very strong and as such, I don’t see much chance for any development over the next five to seven days.

Meanwhile, the Pacific continues to put on quite a show. Hurricanes Kilo, Ignacio and Jimena all remain out over open water, far from land. The record pace of the Pacific season is not just due to the El Nino but a warm north Pacific as a whole, something we have not seen in quite a while.

TD 14-E track map from the NHC

TD 14-E track map from the NHC

In the east Pacific, TD 14-E is forecast to strengthen in to a tropical storm as it tracks generally northward. However, conditions do not appear to favor a hurricane forming out of it and even if it did, weakening is indicated later in the forecast period. I see no reason for this to be an issue for the Baja or elsewhere along the Pacific coast of Mexico.

That’s it for now. Enjoy the fairly quiet start to September. This is typically the busiest month of the season, even in El Nino years. Will we end the month without a hurricane strike along the U.S. coast? Only one way to find out!

I’ll have more tomorrow.

M. Sudduth 11:30 AM ET Sept 1

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