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Goodbye, Dennis, Hello Emily!

By: Dr. Jeff Masters, 5:20 PM GMT on July 11, 2005

The tropical wave that spun off the coast of Africa last week has acquired enough deep convection to be classified as Tropical Depression Five. I've been trying hard to ignore this one the past few days, because tropical waves in July NEVER develop into tropical storms so far out over the Atlantic, DUH! Well, DUH! This is the hurricane season of 2005, and Hurricane Dennis has already shown we need to re-write the rules. A check of the Historical Track Chart for this area shows only four July tropical depressions have formed so far out, and none of these ever made it to hurricane status. So ordinarily, I would say that this storm is probably nothing to worry about; conditions are marginal because sea surface temperatures are fairly cool over the mid-Atlantic. I've seen tropical depressions like this one fizzle and die many times. But I've learned my lesson. This is the hurricane season of 2005--and I fully expect this storm (soon to be named Emily) will become another major hurricane that will threaten the Caribbean and U.S. That's a pretty bold statement for a mere tropical depression in July way out over the open Atlantic, and statistically, the odds of me being correct are probably less than 20%. I hope the statistics are right, and I am wrong. But this is the hurricane season of 2005. The normal rules do not apply.

Where will TD 5 go? Well, a check of the Forecast Verification Chart for Hurricane Dennis reveals that the Navy's NOGAPS model was the best performer. The official NHC forecast was also quite good. The NOGAPS model (and not coincidentally, the official NHC forecast) both bring TD 5 into the central Caribbean. Its way too easy to speculate where the storm will hit land, but I've already been telling my friends who have travel plans to the Caribbean this week to rethink them.

Dennis turned out to be an average major hurricane for Florida, thanks to the sudden weakening that occurred in the few hours prior to landfall. Sudden weakening has afflicted the past three Category 4 hurricanes to threaten the Gulf Coast--Hurricane Opal (1995), Hurricane Ivan, and now Dennis. The reasons for this are probably due to the colder water that typically lies near shore, and the entrainment of dry air from the steering trough to the west. Luck is also an important factor--hurricanes go through natural cycles of intensification called eyewall replacement cycles, and we were lucky Dennis finished its intensification cycle 12 hours before hitting land. This luck does not always hold, as we saw when Hurricane Camille hit the same area of coast at the peak of it intensification cycle.

By coming ashore in a relatively unpopulated beach area, Dennis' damage total will have a tough time catching up to Ivan's $13 billion dollar price tag or Charley's $14 billion. Preliminary estimates peg the damage at $2 - $10 billion, still worthy of a place on the list of the most damaging hurricanes of all-time. Once again, Mobile and New Orleans got very lucky--just a small shift in course could have brought the core of this powerful hurricane over either city, causing incredible damage. One wonders how much longer the Big Easy can escape the Big One; the stretch of coast just to its west has seen two major hurricanes and two strong tropical storms (Arlene and Cindy) in the past year alone.

One also has to wonder about the location of the past four major hurricanes--Ivan and Dennis followed almost identical paths, as did Frances and Jeanne on Florida's east coast in 2004. If I lived in Punta Gorda, where Charley hit last year, I'd be a little nervous watching Tropical Depression Five east of Barbados, wondering if a repeat Charley hurricane might be in the works! This is VERY unlikely, though; direct strikes from major hurricanes are extemely rare for the Gulf Coast of Florida south of the Panhandle. Hurricane Donna (1960) and Hurricane Easy (1950) were the last major hurricanes before Charley.

Dr. Jeff Masters

The views of the author are his/her own and do not necessarily represent the position of The Weather Company or its parent, IBM.

Reader Comments

Wakulla County south of Tallahassee is in some places, like St. Marks under 8-10 feet of water. CNN has a video on their main page with their correspondents boating up and down the street. While Dennis passed almost 170 miles to the West, an interesting storm surge dynamic set up and apparently funneled the Gulf waters up the St. Marks river, to the utmost surprise of residents.
That so many storms have hit the golf coast of florida is not that strange.
The fact that so many have been major
hurricanes and that nearly all the storms
have become major hurricanes, now that is
odd. I have lived in Florida since 1964,
initially on the gulf coast and remember
getting at least 2 or three in one year,
but they where mostly small, cat 1 at most.

Dr. Masters--Do you think that global warming is a contributing factor to the warmth of the Atlantic and the increased storm activity so far this season?
No kidding - Charley is now a verb here, as in we got "Charleyed". Believe me, we are watching very carefully. What concerns us most is the sudden right turn when a storm is paralleling our coast. Or, as in the case of Charley, when it is forecast to hit farther up the west coast and takes one of those infamous "wobbles". We have learned from hard experience that if we're in that cone to any significant degree, we get prepared! BTW, I live in Cape Coral, about 15 miles south of Punta Gorda. We got Cat 2/1 conditions here and a bunch of tornadoes - still no fun, but not like they got just north of us!
I am going to see if I go two for two here with soon to be Emily (Dennis I did pretty good 4 days out). Also turns out I was wrong to concede about my prediction of a 5th tropical system forming from a African Wave.

I think Emily will hit the Texas, Louisiana border as a cat 2 hurricane. My reasoning is:

Dennis will still have enough push to keep the system from riding two far north, along with the strong high pressue near Eurpoe pushing it along

Between land (ie islands), wind sheer and water temps being still somewhat cool until it hits the Caribbean will limit its grow (I do not see it slowly down enough to be able to soak in the warm waters of the gulf).

even IF td5 is to attain hurricane status by the weekend, the mountains of hisapanola and cuba will most likely damper and disrupt the storm significantly (poor haiti!!). needless to say, we all must be looking for something to talk about....because a storm that could realistically become a threat to florida again this early in the season and that far out is NEARLY impossible. i will be very surprised if this storm will cause a major concern for us.

Some predictions by me..if anyone is interested. Would love to hear your comments as well.

Do we have twins here?
Don't forget about Hurricane Lili a few years ago weakening significantly as it approached the coast of Louisiana.

IMHO I think global warming is a factor but not the total cause of the increase in number and power of hurricanes but merely a cycle in which alot of people have taken from granted (ie having been thur about 40 years of average to below average hurricane seasons). Also remenber we only have a little of 100 years of weather data, their may be thousand year cycles we are totally unaware of.

the mm5fsu picked up these twins forming from their models done on early on saturday. the gfs also briefly picked up on these two storms, ultimately the second developing better in both cases. interesting how none of the models picks up both of these currently? or do they??
The GFDL picks up on TD5 and makes it a Cat 4 before smashing square into the Dominican Republic.

I also live in Cape Coral. Moved down here from the Northeast in the spring of 1994 to escape the blizzards and cold. Somehow, when I read the area's promotional literature, I missed the section on hurricanes. Ditto on the worry about any storms or hurricanes taking an oblique right after they've entered the Gulf. It could be another interesting weekend if soon to be Emily tracks into the Gulf. Should have left my storm panels on the house.
again, for this scenario to occur and take the "right hook" into the west coast, would be extremely unlikely......although there is always a chance (as we saw last year)

This is the CMC model 72 hours out. It is picking up T.D. #5 just west of the Lesser Antillies and another low pressure area between the Cape Verde and Lesser Antillies. This is looking to be a VERY VERY busy season.
Here's the MOT (mother of twins) theory of dual hurricane development: One twin is always bigger and stronger than the other from early development until shortly after birth. The larger twin robs energy from the smaller, weaker one. In extreme, but not particularly rare cases, the larger twin is so greedy that it develops too quickly, robs the weaker one of everything, and neither survives. We're in early hurricane gestation with the 'twins' right now. Looks like some models predict 'twin transfusion syndrom,' which could doom both. Others predict the development of both, but one less organized and weaker than the other. We'll see what happens in the next few days.
as I said earlier, that both the gfs and the mm5fsu picked these features up on saturday. i agree this could be a very interesting season. but we've also seen very busy seasons early on, only to have little or no activity the rest of the season.
also, i favor twin #2 to develop more than td5
~Waving discretely and politely clearing my throat~ Um, guys? When you're talking about what parts of the US might be affected by all of this tropical weather, please remember that part of the US sits in the middle of the Caribbean. As proud Americans and residents of the US Virgin Islands, we'd it appreciate it if y'all would take into consideration that the first Americans who are affected by a number of the storms that eventually reach the US mainland actually live more than 1000 miles southeast of southern Florida and Key West. Sorry to butt in...please continue! I'm so grateful to have y'all out there keeping an eye on things (bad pun unintended, and deeply regretted). Thanks!
Bob Hart's MM5 uses the GFS 0.5 degree global forecasts as boundary conditions for the ~1/3 degree MM5. He dropped in a weak bogus (or fake storm circulation) for TD5 yesterday, but did not for the Saturday runs, which were focused on Dennis. The current storm sitution mimics 2004 when Jeanne was over Haiti, Karl (and Lisa) over central Atlantic, and the leftovers of Dennis (Ivan) developing into a decent extratropical trough over Nova Scotia. These ingredients together in 2004 eventually forced Jeanne on a looping track due to that trough before the ridge built behind and slammed it into Florida.
extremely good point cruciancrip!! not to mention we must also consider any other country that might be affected by any of these storms too.
thanks for the clarification on the saturdays models.
Dr Masters...love your blog...but the recent storms have made landfall EAST of New Orleans...if they had been to the west, then I doubt there would be much of New Orleans left
Hurricanes and global warming! Now there's a controversial subject. I am gathering the material to write a rather lengthy blog entry on this. The basic points:

1) No increase in hurricane activity has yet been observed due to global warming.
The current upswing can be attributed to the natural cycle of the Atlantic thermohaline circulation.

2) The theoretical upper limit of strength for a Cat 5 hurricane will increase up to 10-15% or so if you have a warmer ocean.

3) The ocean area over which hurricanes can form will increase.

4) The number of hurricanes may increase or decrease, depending on how El Nino and vertical wind shear over the tropics change in a warmer world. Current models are not good enough to predict these changes, are unlikey to be good enough for a very long time.

If this hurricane season ever takes a break, I will write more on this topic!

Dr. Jeff Masters
I eagerly await your entry about global warming!
I predict Emily will miss the Dominican Republic to the N and curve NW, striking Miami-Dade at Cat 3 and crossing the Florida peninsula, exiting the Gulf coast between Tampa and Sarasota as a tropical storm, then making landfall again near Apalachicola at Cat 1 before dissipating inland. How's that for going out on a limb???
Pretty far limb! Let me join you on an adjoining branch. Considering that the storm is still moving west...the models are walking south(because they were to far N during genesis), and the models forecast and the vapor inidicates ridge building to keep it S of Hispaniola and Cuba, my call is for a brush of N Yucatan and a NE TX/LA strike. Emily will strengthen faster than the NHC forecast and be a strong cat 3/weak 4 S of Puerto Rico.
okay now let me join the ridiculous premature predictions by spliting the difference, and take emily in the worst possible track. she goes north of hispanola and cuba, but south of florida and the bahamas. opening the scenario of the feared right hook to the north, and striking the florida west coast. now all we need are a few predictions for her to hit the carolinas, and a few for MS, and AL, then, we'll have all the bases covered!
I'll have to say, being in the Tampa bay area, I hope wxgssr is right!! But, TampaSteve was very close to being right on with Dennis. I just hope that evolution is way off!!!!!!! :-)
BTW - I'm new to this blogging thing...found it during Dennis. Very much enjoy reading everyone's posts!! Something else to do other than watch the weather forecasters while waiting for the thing to go by!
I want to change my forecast it going to make a beeline north carrying all the hot water with it and increaseing in sign to bigger than Super Typhoon Tip with a pressue south of 600mb and wind speeds in excess of 400MPH slaming into NYC middle of next week with enough force to be a hurricane as it comes out on the Pacfic Ocean side around San Fran near the end of the month (LOL).

Seriously its nice to try and predict where a hurricane is going to go, but remenber most of us are novices and this art and even the experts are no where being 100% all the time. So please anyone reading predictions from this blog and not the offical NOAA forecasts remenber that we are not experts (well most of us are not).
Here we go again!
This is the earliest date on record for the formation of five named tropical cyclones! The Subtropical ridge should keep Emily on a WNW track threatening Haiti and Cuba over the weekend. After that it's speculation.

Looking at this, the way the storm is moving and all of the models, it seems to me that it will go south of Cuba all together. I too am looking at a Yucatan hit, on the north tip, and then a turn to the north, striking somewhere between TX/LA border and Fl/AL border. I dont think it will be as strong as Dennis or Ivan when it makes landfall on the continental US.

US Virgin Is, I think you will be ok with this one, besides a little rain.
Here something of interest. On NOAA they list average storms per month (http://www.aoml.noaa.gov/hrd/Landsea/deadly/Table8.htm )

For thoses that don't want to look here is the breakdown

July - 0.9 tropical system average
August - 2.8
Sept - 3.5
Oct - 1.8

As of right now we have had 5 systems putting July at about 555% above average so if we do the math

August - 15.54 tropical systems
Sept - 19.24 tropical systems
Oct - 9.99 tropical systems

If I am correct they are going to have to fiqure out what to name storms after the they run out of names. Since that would be almost 50 tropical systems this season.
cherikm...yeah, I did have it pegged pretty good...but so did the NHC...hats off to them! Dennis was radar-locked on Gulf Shores right up until the end, then it did that hook to the North...those last-minute "adjustments" are pretty common...that's why you have to allow a 50-mile error zone for landfall. Once the leading edge of the circulation starts interacting with land, strange things can happen.
I think Emily will hit North Carolina as a Cat3 or 4 hurricane.
The latest data seems to suggest that the Bermuda-Azores High will remain strong and take Emily towards Texas or Mexico. The historical data suggests this as well as it is not likely to recurve in the presence of the prevailing strong subtropical ridge.
Texas or Mexico assuming the ridge does not break down, which is not likely. But then how likely is 5 named systems in July ???
Long range models indicate pretty good TROF coming out of the Rockies into the plains as Emily gets into the Gulf. I think this is the feature that will steer her towards upper TX/LA.
I'm going to side with those predicting a Gulf of Mexico eventual strike. The east coast just doesn't look too likely considering the current guidance. If I were Fidel, I would consider an early retirement -- somewhere in Canada.
Of course, that far ahead is somewhat speculative on my part mostly based on the climatology and the 5 day outlook for the prevailing ridge.
I say Pascagoula :)
The atmospheric conditions coupled with Emily's track are amazingly close to a a lil' ol storm we had in '88 named Gilbert.
Hmmm...Emily is tracking further South...I hear ya about Gilbert, but that was mid-September...Yucatan, anyone???
I too am voting for a path south of the Greater Antilles. One thing I wonder about is if Emily will follow the example of Allen, thread the Yucatan channel and then hit Mexico or TX. Allen was in the first 10 days of August, so not so far away in time from Emily.