Ernesto's Landfall Surprise

Along with the NHC, I had believed this morning that there was no chance for Ernesto to strengthen significantly in his 18 or so hours back over the Atlantic. We were wrong, and Ernesto made it almost back to hurricane strength before coming ashore at Long Island, NC.

Hurricane John, meanwhile, blew a tire while scraping up against the Mexican coast, and dropped rather suddenly back to a Category 2 storm. The curve of the land is putting him further out to sea now, and he has a little bit of a chance to reintensify, but the good news is he will probably hit Baja California as only a Category 2, or maybe Category 3 storm instead of the expected Category 4.

Hurricane Kristy is still being a harmless little storm, and surviving well under outflow from the much bigger John. This situation won't last long, and John's eventual westward turn will spell the end of Kristy in one way or another.

The beginning of the end may finally be here for the amazing Super Typhoon Ioke. She's down to 150 mph winds now, and if those drop any further, she'll just be Regular Old Typhoon Ioke. Still, the models call for her to maintain at least Category 4 strength for another 48 hours before the shear kicks in. She'll still be a major typhoon for another day or so after that, but by then she'll have drifted far enough north to start running out of hot water, and the end will finally be in sight.

Ernesto's Last Chance

Ernesto has finally cleared Florida, and is back over the waters of the Atlantic Ocean. The passage over the peninsula took a toll on Ernesto, and he's only a tropical depression at this point. Still, he's got some rain bands kicking up offshore and will probably become a tropical storm again soon. He's got a brief chance to strengthen before his date with the Carolinas, but won't get a chance to do much. At best he's got an outside chance at 55 mph winds. Most likely they'll be in the 45 mph range that Ernesto sustained across Cuba and South Florida.

The Pacific has the big stories of the day. Hurricane John is sliding up the Mexican coast. He was a Category 4 storm earlier today, but has dropped back to Category 3 with a current eyewall replacement cycle underway. He should be back up to Cat 4 tomorrow. The official track makes a sharp left turn once he reaches Baja California, but the model suite is dividing into two camps. The NOGAPS and GFDL want to keep John going northward instead of making that turn. Dr. Jeff Masters notes that theoretically one of the few ways that an Eastern Pacific hurricane could affect the U.S. is to go straight up the Gulf of California. The warm waters are there, but it's an incredibly long and narrow target for a storm, and none in history has managed to do it without hitting one of the coastlines and dissipating. I would note that the GFDL track is very close to going right up the right side right now, and has been trending slightly westward with each run. John may just be getting ready to try...

The other big Pacific story is Super Typhoon Ioke which is about to run over Wake Island. Ioke is packing an 18-foot storm surge (much lower than Katrina's because water has more room to spread out in the wide open Pacific, and has no shoreline to pile against) with a 50 foot significant wave height on top of that. Essentially this means that every third wave generated by Ioke is reaching up to 68 feet above sea level or higher. This will be more than enough to totally submerge Wake Island. The entire population has been evacuated to Hawaii, and nothing on the island except the concrete military structures is expected to remain after the storm.

Finally, John's little sister Kristy is just short of hurricane strength herself. She'll probably get a brief run as a hurricane out at sea, and there may be some interesting interactions between Kristy and John later on.

Atlantic 2006, the anti-2005?

It seemed like last year, whenever there was doubt as to whether a tropical system would intensify or fizzle, you could take the sure bet that it would intensify, sometimes beyond belief. This year, the opposite seems to be true. Alberto just missed being a hurricane, and Chris and Ernesto both had realistic possibilities of becoming extremely powerful storms, but none of the chances played out. Wind shear did in Chris, and Ernesto detoured over land masses. It appears the run of bad luck that the U.S. had 2005 (and 2004) may be over. Does this mean that the active year last year was an anomaly? To some extent it was. You won't get a record-shattering year every year. On the other hand, 2006 may still be lulling us. September and October can still be very active, and there will still be probably at least seven more storms out there this year. Any one of those that makes it into the Gulf could still cause havoc. But it's good to see a little break of at least a few months, after the relentless barrage of 2005 and 2004.

Right now, Ernesto is drenching South Florida, but with only 45 mph winds, not causing tremendous damage. He should be just a tropical depression by the time he comes back offshore. The GFDL is really enthusiastic about Ernesto's future, making him a hurricane again before his encounter with the Carolinas, but the NHC is more doubtful.

Right now the action is in the Pacific. Hurricane John is moving just parallel to the Mexican coast, and is just now getting large enough that he's barely starting to scrape the coastline with tropical storm force winds. Conditions look favorable for intensification, and John will probably be a Category 4 storm tomorrow. It should be noted that track that curves John to the west just south of Baja California is only one of two model solutions. The other track would take John northeastward and towards landfall at that point. John may be the relatively rare Pacific storm that makes landfall in North America.

Ioke is now once again an incredible Category 5 Super Typhoon. She's held this strength for 6 hours now, and is forecast to hold this strength for another 36 hours. Even after that, Ioke is still forecast to maintain Category 4 strength for a considerable time afterwards.

UPDATE: The NHC is about to declare that this blob west of Hurricane John is Tropical Depression 12-E. And they are predicting this will be Tropical Storm Kristy by tomorrow.

Say Hello to John

Tropical Storm John, the Pacific's newest, is soon to be Hurricane John. He's going to be sticking close to the Mexican coast, so he'll have to be watched for any sudden right turns that could make him make landfall. As the official track goes, he'll probably stay out to sea, but could cause some nasty waves and rip currents while he's intensifying.

IOKE UPDATE: Yes, Super Typhoon Ioke is still out there and still maintaining 150 mph winds, and kicking up 46-foot waves. Ioke is expected to put on one last burst to make Category 5 for a while again, but that may be the beginning of the end. Finally, a Category 3 intensity is back in the forecast for next Saturday, which would make over 9 days consecutively at Category 4 or 5.

Caribbean Islands 2, Ernesto 0

Earlier I pessimistically reported that Ernesto was certain to cause a large loss of life with his unexpected arrival in Haiti. Fortunately, it appears Haiti got the better of that encounter. The mountainous terrain simply quickly ripped Ernesto to shreds. The death toll in Haiti is still officially two. It is too early to call this the final total, since rural areas will likely be slow in reporting, but it is evident that Ernesto didn't cause the same massive destruction in Haiti as Jeanne did two years ago.

Ernesto's encounter with Cuba was likewise unfavorable to Ernesto. When he finally emerges back over water tomorrow morning, he's likely to be no more than a minimal tropical storm. The further good news is that Ernesto should no longer have enough time over water to become a hurricane again. He should remain a fairly weak tropical storm as he tracks northwards across Florida. The last possibility that he has for any significant restrengthening would be as he comes offshore briefly between Florida and South Carolina. The Gulf Stream waters there should be warm enough to allow Ernesto to regain a little strength, but 70 mph is probably his upper bound. This is a classic case of why it is so hard to accurately predict the intensity of storms. A relatively small difference in Ernesto's track over the weekend took Ernesto mostly over the islands rather than over the nearby super-hot Caribbean and Gulf waters. That makes the difference between 40 mph and 140 mph sustained winds.

So far the 2006 hurricane season is looking pretty gentle compared to 2005, but we still have over half the season to go, and it is no time to relax the guard.

Ernesto's track trending eastward

Each consecutive forecast pushes Ernesto's track further east. It now looks like most of the Gulf Coast is in the clear for this storm. Florida and the Bahamas still need to keep preparations progressing. In fact a non-resident evacuation is in progress in the Florida Keys. Ernesto's track into Haiti has knocked him down from a minimal Category 1 hurricane to a 50 mph tropical storm. The same areas where 3,000 people died in floods and landslides triggered by Tropical Storm Jeanne in 2004 are receiving up to 20 inches of rain today. One death has been confirmed in Haiti, but it would be miraculous if that number doesn't increase greatly.

If Ernesto stays over Cuba long enough, there might not be anything left to hit Florida. The NHC is being cautious and assuming that Ernesto will still pop off the coast of Cuba as a tropical storm. That would give him enough time to rebuild to hurricane strength before hitting Florida, but the new track misses most of the incredibly hot waters that could drive explosive intensification.

IOKE UPDATE: Super Typhoon Ioke has weakened to a Category 4 storm, just below Category 5 intensity, so no Category 5 record right now. The forecast still keeps Ioke at Category 4 or 5 throughout the week, so the Category 4/5 record could still be broken.

Ioke's record run continues

Hurricane Ioke has become Super Typhoon Ioke this morning, and is still a huge and impressive storm with 160 mph winds. Actually, Ioke's officially defined sustained winds are now 120 mph, but that's only because Ioke has entered Japan's monitoring area, and the Japan Meteorological Agency uses a 10-minute average to define sustained winds, while the U.S. uses a 1-minute average. Currently the 1-minute average of Ioke's strongest winds is estimated at 160 mph, while that averages to 120 mph over a 10-minute span. Ioke has now been at Category 4 or stronger for 60 hours, and Category 5 for 24 hours. The forecast calls for Ioke to maintain Category 5 strength for the next 5 days. If so, Ioke will break the previous record of Super Typhoon Nancy of 1961, which maintained Category 5 strength for 132 hours.

Ernesto takes a deadly turn

Ernesto unexpectedly jogged northward last night while strengthening to hurricane strength, and will shortly brush or make landfall in Haiti. This situation developed overnight and likely took Haiti completely by surprise. Even a weak storm can cause deadly flash flooding on Haiti's deforested slopes, and Ernesto is already at hurricane strength and is still strengthening pretty rapidly. The death toll from Ernesto in Haiti will easily reach the hundreds, and may even be in the thousands. I would expect Ernesto's name to be retired after this year.

Ernesto looks like a Dennis clone right now

The shear in front of Ernesto forced the center to relocate northward during the day, and the tracks have been adjusted accordingly. The current NHC forecast, in fact, bears an uncanny resemblance to last year's Hurricane Dennis. Of course, remember that the skinny black line has been adjusted all over the place so far, and will continue to be. Even though the NHC is now calling for Ernesto to eventually end up by the Florida-Alabama state line, Louisiana and New Orleans, and the entire Florida Gulf Coast are still realistically at risk.

TROPICAL GRAB BAG: Debby is looking mighty depressed after her downgrade to a tropical depression. That's pretty much the last we'll hear of her. Ileana is likewise fading fast. Ioke on the other hand, is a truly astounding force of nature. With 160 mph winds, this 460 mile wide storm has now been at Category 4 or higher for 48 hours consecutively and shows no signs of stopping. As she crosses the International Date Line in the next few hours, she'll become Super Typhoon Ioke, and thus is being handed off from the Central Pacific Hurricane Center to the Japan Meteorological Agency Typhoon Center.

Ernesto vs. Upper Level Low

This is the story that everyone in the Caribbean and along the Gulf Coast needs to be following right now. Just in front of Ernesto, and moving westward like he is, is an upper level low. That's the coil of orange wind arrows south of Cuba in this shear diagram. Note the pockets of strong (30-40 mph) shear surrounding it. Both Ernesto and the low are moving west, the critical question is which will move faster. If they move at about the same speed, Ernesto will remain under 10-20 mph shear, and probably continue to intensify slowly, like he has been doing so far. Under this scenario, it could take a few days for Ernesto to reach hurricane strength. If the low is moving faster, then shear will decrease over Ernesto, and he could reach Jamaica as a Category 1 hurricane, and be a major Category 3 hurricane by the time he reaches the Gulf of Mexico. On the other hand, if Ernesto is moving faster than the low, he'll reach that zone of 30+ mph shear and be ripped apart. Dr. Jeff Masters notes that predicting the motion of upper level lows in the tropics is still a weakness in the major computer models. It's almost a guessing game to see which scenario would play out.

The NHC is sticking with the low moving faster. Right now their predicted track forecast is looking pretty bad for the areas of Louisiana and Mississipi hit by Katrina almost exactly a year ago. This is only one possibility, though. The "spaghetti diagram" shows that there is quite a range of variation in where the computers think the storm will go. One possibility is that Ernesto can slip northward through a gap in the ridge to his north. This would send him recurving across Florida. Or he could just slide up the ridge towards New Orleans. The ridge could also strengthen and force Ernesto towards Texas.

Ioke: One for the record books

After a brief dip into Category 4 territory late yesterday, Hurricane Ioke is back to Category 5 intensity, with 160 mph sustained winds. The central pressure has also come down to 920 mb today, breaking Ioke's own previous record of 921 mb for a Central Pacific storm. In addition, the Central Pacific Hurricane Center believes that Ioke may be threatening the world-wide longevity record for a Category 4/5 storm. Ioke has now been Category 4 or 5 for the past 42 hours consecutively, and is forecast to remain at this strength for another 5 days. There is really no reason to doubt this forecast. There is a very favorable upper level environment in the region, really warm seas, and no land masses for thousands of miles. Ioke also has already set a type of artificial and informal (but still interesting) record for the GFDL computer model. This frame of the latest GFDL run predicts a central pressure of 874.6 mb (only 4.6 mb above the real life record of Super Typhoon Tip). Dr. Jeff Masters indicates that this is the lowest ever pressure that the GFDL model has ever produced.

UPDATE: The latest GFDL run now makes Ioke break Tip's record.

Early stages of Ernesto

Ernesto was having some problems with shear today, with the low level center becoming almost completely exposed at times, but what convection is there is looking pretty darn good now. Ernesto's still got a challenge over the weekend to survive what should be the strongest shear he'll encounter. After that, the models are predicting low shear the rest of the way across the Western Caribbean and into the Gulf of Mexico. The NHC projected path mostly keeps Ernesto south of Cuba if he survives. Note that the 5 day cone now extends as far as Louisiana, so people in that area should be watching the situation carefully. A lot can change quickly early in the development of tropical cyclones so it's too soon to say that anywhere except the southern coast of Haiti (where they have put up a Tropical Storm Warning) and probably Jamaica (where the island is under a Tropical Storm Watch) will be affected by this storm. But the most recent run of the GFDL model makes Ernesto into a Category 3 hurricane just about to hit Louisiana by next Wednesday evening. This is only one potential scenario based on one run of one model, and not a forecast, but it's something to keep in mind as one realistic possible future for Ernesto.

Ioke: First-Ever Category 5 Central Pacific Hurricane

UPDATE: I didn't realize it when I first posted, but this is the first storm to have formed in the Central Pacific to reach Category 5. All the previous Category 5 storms in the Central Pacific (between 140 W and 180 longitude) have drifted there from somewhere else. The 921 mb pressure is also a record low.

Ioke has become a pretty impressive storm, with 160 mph winds, and a central pressure of 921 mb. After all, this is the Central Pacific we're talking about, and the storm can go hundreds of miles without getting near anyone. Right now there's very little to stop Ioke, and I expect the only thing that would take her below Category 5 in the next week or so would be an eyewall replacement cycle. There's no land to make landfall or to cut off moisture or circulation for the storm, and shear will remain low for now, and category 5 storms tend to create their own upper level environment that acts as a shield against shear anyway. Ioke will be around for quite a while, even when she becomes Typhoon Ioke soon.

Tropical Depression 5 is now at its make or break stage. Shear is as high as it's going to get in front of the depression. I expect this cyclone to be either completely gone or a strengthening Tropical Storm Ernesto 36 hours from now. If Ernesto survives, look out, because the conditions further along are very good for strengthening. It's not too early for people in long-evacuation-time areas like the Florida Keys to make final checks of their hurricane preparations. You may have to put your emergency plans into effect in another few days, depending on the track of this storm.

Ernesto about to make an appearance

The tropical disturbance I mentioned earlier near the Lesser Antilles underwent some major changes today. The circulation center approached the Venezuelan coast too closely, and had its moisture and convection inputs cut off along the southern side. This caused the incipient depression to reorganized further north around a new center. Shortly after this occurred, NHC hurricane hunter aircraft found that it had established a new closed circulation and become Tropical Depression 5. There are still a few unfavorable obstacles that this system will have to avoid, but I'm pretty sure we're soon to see Tropical Storm Ernesto here. Right now there is a fair amount of Saharan dust in the path of this depression, which should at least temporarily inhibit the system from strengthening. Shear could also be a problem, but I tend to believe the GFS and GFDL models are correct in moving the upper level low westward out of the way of an intensifying Ernesto. For right now, this system appears to be ready to become Tropical Storm Ernesto, and then threaten Jamaica and the Cayman Islands as Hurricane Ernesto. Assuming it avoids the larger islands after that, it's got a very favorable Gulf of Mexico in front of it in terms of sea temperatures and shear. This could be a big one. The Gulf Coast from the Florida Panhandle through Texas should be watching the future of this storm.

OTHER TROPICS: Debby is still out there, but not much of a concern to anyone. She's staying out to sea, and is no longer predicted to even make hurricane strength. Ileana is fading rapidly as expected as she reaches much cooler waters. Ioke suddenly intensified to Category 4 today, and is looking very impressive over the open waters of the Pacific. Within 72 hours, Ioke should cross the International Date Line, still humming along at around this intensity, and thus become a typhoon.

Ileana doesn't prove me wrong again

Hurricane Ileana decided to play nice and intensified to a Category 3 hurricane overnight in the middle of some very good conditions for strengthening. Good. It would have been really embarassing to have another hurricane only reach Category 2 right after I claimed that doesn't happen much anymore. Ileana is looking really healthy right now, and should reach Category 4 tomorrow. The storm's track remains far offshore, though, and there is no threat to land.

Meanwhile in the Atlantic, Debby is still chugging along and slowly organizing. This should continue through the end of the week, and Debby should be a hurricane somewhere east of Bermuda by then. She also won't threaten land.

Debby Declared

Tropical Depression 4 finally strengthened into Tropical Storm Debby with 40 mph winds. Debby's naming was at 28.9 degrees west longitude, so by the statistical rule, she will be no threat to North America. Indeed, the computer models all agree that she'll follow a trough of low pressure to the northwest over the open Atlantic. While she'll likely become a hurricane, she's not a threat. What may be a threat is the blob of storms approaching the eastern end of the Caribbean. Most models make this blob into a tropical storm (Ernesto) in the Caribbean by Saturday or Sunday.

Pacific Update: Ileana is now an impressive-looking hurricane with 85 mph sustained winds. She's now looking to peak at Category 3, but stay off-shore. Hector is still very slowly fading away as a tropical depression. Ioke hit Johnston Atoll today, not that anyone was there to watch it. A collapse of the eyewall took Ioke down to Category 2 at the time. Conditions are still OK for Ioke to maintain this strength for a few days.

Tropics heat up quickly

Some pretty rapid changes occurred today in both the Pacific and the Atlantic. While Hector is back to a 40 MPH tropical storm, and fading quickly, three new storms have popped up. The most notable is Hurricane Ioke which has in 48 hours gone from a just-forming tropical depression to an impressive Category 4 hurricane. See what happens when I take a little break? Ioke is staying well to the southwest of the main Hawaiian Islands, but could pose a threat to the sparsely populated islands and atolls that make up the Northwestern Hawaiian Islands. The U.S. territory of Johnston Atoll lies directly in the path of Ioke, and will take a vicious hit tomorrow. Johnston Atoll has been uninhabited for over two years now, and is now officially a wildlife refuge. Many of the last remaining traces of the former human habitation will doubtlessly be destroyed by this storm, returning the island to an even more wild state.

The newest member of the Pacific Storm family is Tropical Storm Ileana. Ileana should stay well offshore, but may set out to prove me wrong again by attaining only Category 2 before slowly fading out west of Baja California Sur.

The latest in a series of impressive tropical waves coming off of Africa has organized enough to become Tropical Depression Four. Strengthening is anticipated, and this should be Tropical Storm Debby by tomorrow. This is actually good news. Storms that get named (i.e. sustain 39 mph or stronger winds) before crossing west of 40 degrees west longitude rarely make landfall in North America. Debby should get named somewhere around 25 degrees west. While Debby will likely become the first hurricane in the Atlantic this year, she's likely to slip northward into a weakness in the Bermuda High, and move into a latitude where the prevailing winds will recurve her back eastward without approaching any land. It takes a strong and persistant ridge of high pressure to keep a storm that forms this far east from turning north before reaching the Lesser Antilles.

Will Hector make CAT 3?

It's my informal observation that recently any storm that intensifies to Category 2 will continue to intensify at least to Category 3. Hurricane Hector may be attempting to challenge this. Right now Hector is a Category 2 hurricane with 105 mph winds. He is also predicted to be close to his peak intensity right now. It would take only a small round of intensification, however, to put Hector into Category 3 in the next 12 hours. If he doesn't make it during that window, then the weakening trend will have begun, and Hector will have proven me wrong.

Nothing going in the Atlantic / Pacific pops up Hector

The lows being tracked in the Atlantic for possible development aren't doing much today, but Tropical Storm Hector has developed in the Eastern Pacific. He's going to have a shot at developing into a hurricane tonight or tomorrow, but should stay well away from land.

Welcome Back, Me

I'm back online, so here's a brief summary of what will be coming soon in my next few entries: We have the end of an old cold front that's turned into a non-tropical low, that's very slowly trying to convert itself into a tropical storm. Right now, this one looks nearly exactly like a replay of the genesis of last year's Ophelia. There's also a strong tropical wave moving across the Cape Verde Islands. It was looking even stronger yesterday, with even some reported 50 mph wind gusts (but no closed circulation). There's also some notable seismic activity going on in the Pacific Northwest and Alaska right now, the still-threatening Mayon volcano, and the aftermath of Saomai.

Saomai makes landfall

Saomai has made landfall just below super typhoon strength, with reported 150 mph winds. China has evacuated 1,300,000 people in the lowest lying areas in the storm's path. Damage and casualty reports probably won't be available for quite some time, as the storm is expected to maintain typhoon strength for over 12 hours inland. (Note that the article I've linked to calls the storm surge a "tsunami". I'm not sure if this is a British usage, or just that since the Indian Ocean tsunami, they expect more people to know what a "tsunami" is than storm surge flooding.)

Super Typhoon Saomai barrelling into Chinese coast

Saomai strengthened today into a super typhoon, equivalent to a catastrophic Category 5 hurricane, with winds of 160 mph, and wind gusts up to 195 mph. It will make landfall shortly at this strength, or slightly below, along the border between Fujian and Zhejiang provinces. Together, these provinces have a population of over 83,000,000. While the hilly and mountainous terrain will prevent Katrina-like flooding, coastal cities could still see 25-foot storm surges. This is sure to add to an already bad typhoon season for China.

No Debby Development / Saomai gains strength

The tropical wave that looked so promising moving westward from the Cape Verde islands is now just about gone. The surface circulation has pretty much disintegrated, and there are only a few disorganized thunderstorms remaining. Dry air drawn into the path of the developing storm seems to have taken its toll.

Meanwhile, over in Asia, several major changes have happened to the three storms I mentioned earlier. Tropical Storm Maria briefly became a typhoon, but has since made a very sharp recurvature to avoid making landfall in Japan. Bopha crossed Taiwan as a minimal tropical storm, and is now downgraded to a depression. While Maria and Bopha both fizzled, Typhoon Saomai has become a very dangerous storm with 145 mph winds. It is expected to maintain or possibly strength as it passes just north of Taiwan, and then hits the Chinese coast betweeen Fuzhou and Wenzhou tomorrow. The inland track of Saomai will take it through some incredibly densely populated areas, and the damage is likely to be devastating.

Cape Verde development looking a little less favorable

While it may still be likely that Tropical Storm Debby will form from this Cape Verde disturbance, she may not be the live-forever Cape Verde storm, that say, Hurricane Ivan was. The reason is the upper level low (that vague swirly donut near the lower right) that she will have to slide by a few days from now. The south side of that circulation will generate a pretty fierce wind shear directly in the face of the tropical storm or depression that comes out of this Cape Verde disturbance. We may still get Debby out of this one, but I think the name is safe from retirement on this go around, and we're pretty certain to also get another Debby in 2012.

Tropical Triplets Threaten Asia / Long-Range Cape Verde Watch

Hot on the heels of Typhoon Prapiroon three more cyclones are clustered just offshore, and each look to make landfall in quick succession over the next few days. The first will be Tropical Storm Maria which will come ashore late Tuesday and track over Osaka. Maria should remain just below typhoon strength. Then China will receive a double punch in a very short time span. First Bopha should arrive at or just below typhoon strength on Wednesday, then the much more powerful Typhoon Saomai will come in just north of Bopha's track on Thursday. All three storms bear watching.

Finally, the Cape Verde disturbance that we have been following should become Debby soon. QuickSCAT readings show that the winds have already formed a closed circulation, and as this disturbance continues to organize and consolidate, there seems to be little in the way of shear or dry air to stop it. Water temperatures ahead along the projected path are already very warm, as could be expected in early August. The only thing that could significantly interfere with this disturbance becoming a depression and then a tropical storm would be if it were to dip south of 10 degrees latitude and start getting interference from the South American landmass. So far none of the models say it will.

Cape Verde action

The NHC is now preliminarily watching this blob of storms moving off of the coast of Africa. This is the disturbance that the GFS had been previously turning into a Cape Verde storm. The Canadian model is still developing this one, but the rest of the models have given up on it for now. It still bears watching through the weekend, though: this is the most likely source for now of a future Debby.

Chris just fades away

Can you find Chris in this picture? Neither can the folks at the NHC. Chris has totally fallen apart into a zone of disorganized low pressure and thunderstorms with only 25 mph winds that may not even be in closed circulation. With the low even drifting further south over Cuba, Chris is done for. Some meteorologists have remarked that "Chris" doesn't seem to be a powerful hurricane name. None of the many storms named Chris have ever been more than just a minimal hurricane. This year's was no exception. Chris will get another shot in 2012.

The drawn-out demise of Chris

Chris is still barely hanging on as a tropical depression: a state he's now likely to remain in for the rest of the time he's around. What's keeping Chris from intensifying according to the NHC is "upper level convergence". Essentially convergence is when a bunch of air from different places is all trying to wind up in the same place. Divergence is the opposite. Tropical cyclones like upper level divergence, because this draws air upwards into the place vacated by the diverging air. Drawing warmer air from near the ocean upwards produces convection, and thus thunderstorms, which give the energy that the storm needs to intensify. In the image at the top of this page you can get a picture of how the rising convection goes along with the air spreading out (or diverging) at the top of the storm. When the air is instead converging at the top, it effectively keeps a lid on the convection, and less energy is released into the storm.

Chris downgraded

Chris is back to a tropical depression this morning with 35 mph winds. It also looks now like he'll be taking a longer path over Cuba, so dissipation there is looking like a very strong possibility this morning. If Chris does survive his time over Cuba, the Gulf of Mexico is still looking to be ripe for reintensification, but Chris is running out of time to have a chance of becoming a hurricane.

Chris tries to regain balance

Chris is again trying to get in place in the "sweet spot" between the upper level lows to either side where shear is the lowest. It looks like he's starting to find it again, with convection again blowing up and re-enveloping the core of the storm. The winds tend to lag behind the convection, so Chris is still a minimal 40 mph tropical storm at this hour. Depending on his exact track, Chris has some potential to make a comeback, or just as quickly fall apart completely. The storm is about to enter the Turks & Caicos Islands, and should then cross the southern Bahamas, and both areas are now under tropical storm warnings. The best track still looks to be just a bit to the north of due west, and up along the northern side of Cuba. This is where a few miles difference in the track will make a huge difference in Chris's future. If Chris ends up spending a long time over Cuba, the storm will probably dissipate, or emerge into the Gulf of Mexico as a weak depression. But if Chris simply skirts the coast, he could possibly maintain up to 50 mph winds. Once in the Gulf, the conditions are looking pretty good for Chris to intensify, if he's still around 4 or 5 days from now. How much intensification there will be will depend on the initial conditions. If he's gone far over Cuba and comes across as a disorganized 25 mph depression, there might be only enough time to regain minimal tropical storm strength. If he enters the gulf as a fairly good looking tropical storm, then he still has a chance of making landfall as a hurricane. Texas and Louisiana definitely need to watch Chris's visit to Cuba carefully.

BONUS DEBBY WATCH: The GFS and Canadian models are still indicating potential for a Cape Verde storm to develop 3-5 days out. Stay tuned.

Chris falls off the tightrope

What a difference in 12 hours. Chris has wandered out of his little corridor of intensification, and shear has just ripped the convection right off of the storm circulation. So much for Chris. He won't be a hurricane any time soon. The remnant circulation will have to be watched once it gets in the Gulf still, if it doesn't dissipate over Cuba, so maybe we haven't heard the last of Chris, but his immediate threat is gone.

Chris gets shoved back south

The GFDL's unlikely looking idea of Chris being forced more southward has begun to look more realistic now, vindicating the utility of the model once again. The reason for this is related to the record and near-record heat and humidity affecting the eastern U.S. right now. The sea level pressure as forecast by the GFS model shows the strong Bermuda High keeping Chris from moving north. As the Northeast heats up, the air is thermally induced to become less dense, and the Bermuda High spreads westward to fill in. This forms an elongated ridge of high pressure to the north of Chris's track, forcing the storm almost due west.

The overall result is that Chris is forced into a less favorable zone for intensification, and thus is less likely to become a hurricane...for now. The latest track also takes Chris across Cuba, which is an easier passage for a storm than over Hispaniola. If the storm ends up going over Cuba with the circulation remaining intact, it could find a much more favorable zone for reintensification in the Gulf of Mexico. Chris may be with us a while still.

P.S. Note that if you went forward to the last frame of the GFS model, you may have noticed the concentric green circles just west of Africa. That's a potential Cape Verde disturbance that the models have been consistently predicting for a while. Cape Verde hurricanes tend to be nature's version of the punch Popeye throws to end a cartoon: there's a ridiculously long windup of the arm windmilling around faster and faster, which finally culminates in the devastating uppercut that sends Bluto over the horizon. That area will have to be watched, starting in about 5 or 6 days. If a potential Debby forms there, she could also be making headlines for a long time.

Good Evening, Santa Rosa!

The northern Bay Area got a after-dinner reminder this evening. From the preliminary information, it looks like this was along one of the strike-slip faults parallelling the San Andreas around Santa Rosa. Mercalli intensities across the region seem to be mostly in the III-V range, so this wasn't more than a good rattle for most people, although it would have been probably an exciting ride near the epicenter. This is almost a bookend to this quake, although they are not likely related. With both being somewhat similar in magnitude and relatively soon after each other, but at opposite ends of the region, this should provide an opportunity to improve seismic mapping of the Bay Area.

Chris Trending North

Chris has continued to balance in the small favorable zone between two upper level lows today. The computer models and actual position of the storm now are starting to move quite a bit north of the islands. The GFDL, though, which is usually one of the best, insists that Chris will still plow into the Dominican Republic and disintegrate. This isn't looking too likely this morning. The best bet still looks as though Chris will cross the Bahamas and either South Florida, or the Florida Keys. These areas are now about 4-5 days out from the storm, and still have time to prepare.

Chris Survives Improbably

Somehow Tropical Storm Chris managed to find a narrow safe path across the mostly forbidding environment for tropical storms that currently exists near the Leeward Islands. Chris is in the lower right and right now it looks like he's going to follow a high pressure ridge right along the outer rim of the Caribbean islands. Chris is just skimming Barbuda right now, and producing some gusty winds. Right now, Chris seems like a good prospect to become the first Atlantic hurricane of 2006, but there are still several pitfalls that could disrupt the storm. If Chris starts drifting more south as the GFDL model predicts, the storm will go pretty much right over Pico Duarte in the Dominican Republic. Tropical storms don't tend to survive when trying to cross 10,000-foot mountain ranges. On the other hand, if Chris manages to drift more northward to follow an upper level low there, the shear will be a lot stronger, and he'll remain a tropical storm, without having the opportunity to strengthen to a hurricane. Finally, there's always the "just right" scenario, which is close to the NHC's best track prediction. In this case, Chris would enter the Gulf of Mexico as a Category 1 hurricane. Once in there, there's a lot of warm water available, but it's too early to get a reliable reading of what the surrounding conditions will look like, or what track Chris would follow more than a week out, but none of the possibilities look particularly good for the Gulf Coast. As it stands, Florida south of I-4, the Bahamas, and Cuba should be preparing for Chris's potential arrival.

TD 3 survives and becomes Chris

Improbably, Tropical Depression 3 strenthened and deepened overnight and is now Tropical Storm Chris with 40 mph winds. The forecast is now looking better for Chris as well. If the storm stays as deep as it is, it may be enough to keep it from drifting over Hispaniola, where the mountains would shred a small storm. As it is, it's not too early for Florida to start watching this system.