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HURRICANE KATRINA |
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by Brendan Loy Hurricane Watches up8/24/2005 10:11:00 AM ESTPosted by Brendan Loy Tropical Storm Katrina is now forecasted to become a hurricane by landfall, and Hurricane Watches are up from Vero Beach southward to Florida City. Here are the latest computer models. Katrina could be a major hurricane at landfall8/24/2005 06:40:00 PM EST Posted by Brendan Loy Russell may have been on to something when he wrote yesterday that Tropical Storm Katrina, then just a nascent tropical depression, could become a monster hurricane before landfall. The official forecast calls for Katrina to hit south Florida as a Category 1 hurricane with 80 mph winds on Friday, but the latest NHC discussion raises the possibility that she may reach major hurricane status: With the improved banding features...symmetrical upper-level outflow...and relatively weak shear...at least steady intensification of a normal rate of 10 kt per 12 hours until landfall occurs seems justified. This is similar to the SHIPS intensity model...but much less than the now very bullish GFDL model which brings Katrina to 111 kt [130 mph, borderline Category 3-4] just before landfall. It should be pointed out that with SSTs near 31c and a low shear environment ... conditions are favorable for possible rapid intensification to occur between now and landfall. This is suggested by the SHIPS model experimental rapid intensification output...which indicates a 57 percent probability of that occurring. The only inhibiting factor is the dry air that surrounds Katrina and has been working its way into the inner-core region and eroding the deep convection. If the dry air mixes out within the next 12 hours...then intensities would likely be higher than the official forecast is indicating. There's also the matter of re-emergence over the Gulf of Mexico. Charles Fenwick at Eye of the Storm writes, "It is a bit soon to rate the probabilities of the scenarios, however, it is worthwhile for residents of the Gulf coast from Mobile, Alabama to St Mark's, Florida to be aware of the possibility of a significant hurricane affecting their area in six days." Fenwick also notes that, thanks to Katrina, the 2005 Atlantic hurricane season has now given rise to the earliest recorded formation dates for the fourth, fifth, sixth, seventh, eighth, ninth, tenth, and eleventh named tropical storms of the season. That's eight consecutive "earliest ever" records! (Details here.) However, the twelfth-storm record is August 28, and nothing else looks too likely to develop at the moment, so that streak may be nearing an end. In other news, I've found some more computer-model maps: here and here. Computer models still confused about Katrina8/25/2005 12:28:00 AM EST Posted by Brendan Loy The 11:00 PM discussion on Tropical Storm Katrina notes: This forecast is rather difficult since one of the more reliable models...the GFS...shows that the cyclone barely touches the East Coast of Florida before moving northward....while the outstanding GFDL moves Katrina south of due west across extreme South Florida and the Keys as a very intense hurricane. The GFDL scenario would be very dangerous for South Florida. This appears to be unrealistic at this time but because of the good past performance of this model...we must pay close attention to future model runs. The GFDL track is the green line on this map. Here's the official track. Katrina almost a hurricane, nearing Florida8/25/2005 02:06:00 PM EST Posted by Brendan Loy Tropical Storm Katrina (seen here on radar) is strenghtening as she nears south Florida, with 70 mph winds as of 2:00 PM. She's expected to be a hurricane (i.e., 74+ mph winds) when the center makes landfall later tonight or early tomorrow. The likely landfall point is near Fort Lauderdale, according to Dr. Jeff Masters. Here's a news article from the South Florida Sun-Sentinel. After hitting Florida peninsula and slowly inching westward, what then? The official track calls for a second landfall, again as a Category 1 hurricane, on the Florida panhandle Sunday night or Monday morning. But there are lots of different computer model scenarios, ranging from the Mississippi Delta to Savannah. Hurricane Katrina8/25/2005 02:55:00 PM EST Posted by Brendan Loy Katrina is now a hurricane. UPDATE, 5:57 PM: Katrina has made landfall.
Here's the latest radar. Katrina is the sixth hurricane to hit Florida in the last two years. But it, at least, is not a major hurricane. We'll see what happens on second landfall. (Official track, computer models.) Nothing like a front-row seat8/25/2005 08:13:00 PM EST Posted by Brendan Loy From the NHC's 8:00 PM EST advisory: ...KATRINA RELENTLESSLY POUNDING SOUTH FLORIDA...CALM OF THE LARGE EYE EXPERIENCED AT THE NATIONAL HURRICANE CENTER... Heh. Christian Wilson, a 1L, writes that his family lives next-door to NHC Director Max Mayfield, and "we only shutter [our windows] when he does." Talk about a personalized forecast! :) As Katrina approached, "He shuttered only the west side of his house because he says the winds are coming from that direction. I found that pretty amusing....a partial shutter situation." Katrina turns south, stays strong8/25/2005 11:09:00 PM EST Posted by Brendan Loy Hurricane Katrina has turned southwestward and sped up a bit, so she will emerge over the Gulf of Mexico in just a few hours. (Radar loop here.) That's good for south Florida, which will get less rain than expected, but bad for wherever this hurricane heads next. Katrina hasn't weakened much at all during her brief sojourn over the Florida peninsula; even now, as the center nears the state's west coast, she's still at 75 mph. The NHC's forecast that Katrina would only attain minimal Category 2 strength over the Gulf was based on the premise that she would weaken to 50 mph first. So her failure to significantly weaken is distinctly bad news, and should substantially change the intensity forecast. With steady intensification expected once the center re-emerges over water, I suspect Katrina will be at least Category 3 at second landfall. UPDATE: Charles Fenwick at Eye of the Storm writes: "More than four hours over land and STILL a hurricane. Remarkable." (Now it's more than five hours.) But Fenwick offers a good explanation for why: "Katrina's southerly course is taking her over the Everglades. The difference between the Everglades and open water is slight." Regarding the track, Steve Gregory says "there is is still way too much uncertainty with the exact timing of the turn northward, and the entire Gulf coast, from Louisiana eastward to Tampa could ultimately be at risk for the next and final, landfall of Katrina." Dr. Jeff Masters says "an area from New Orleans to Cedar Key, Florida at risk. In the center of this risk area lies the U.S.'s very own hurricane magnet, the Pensacola region, where Ivan and Dennis struck." I can certainly understand Pensacolans being nervous. What makes me nervous is that Katrina's southwestward turn and refusal to weaken makes a New Orleans doomsday scenario considerably more plausible than it seemed just a few hours ago. Still unlikely, but more likely than it was. UPDATE, 12:17 AM: Katrina has finally weakened to a tropical storm as of midnight EST, approximately six hours after making landfall. But that won't last long. She's already got her "feet wet" over the Gulf, seven hours ahead of schedule. Well, that didn't take long8/26/2005 07:49:00 AM EST Posted by Brendan Loy As of 4:00 AM EST, Katrina is a hurricane again. She was a tropical storm for exactly four hours. Here's the latest forecast track. It's shifted slightly to the left, but the Florida panhandle is still seen as the likely target. Most of the computer models agree, though the exact location is up in the air, which is not surprising for a landfall that's 3 to 4 days away. The intensity forecast conservatively brings Katrina to 105 mph at landfall, but the discussion says, "It is certainly possible that Katrina could attain major hurricane status [i.e., 111 mph+] before making landfall somewhere on the northern Gulf Coast." Katrina intensifying rapidly; Cat. 4 by Monday?8/26/2005 11:06:00 AM EST Posted by Brendan Loy The National Hurricane Center issued a special advisory a half-hour ago, indicating that Hurricane Katrina has rapidly strengthened into a Category 2 hurricane with maximum sustained winds of 100 mph, and further intensification seems inevitable: Given the rapid improvement in the inner core structure and the sharp pressure drop...rapid intensification seems likely for the next 12 hours or so. Afterwards...steady intensification to near category four strength by 72 hours appears to be in order given the very warm Gulf waters beneath the hurricane and the vertical shear forecast to decrease to less than 10 kt by 48 hours. So where will this soon-to-be-a-monster hurricane go? The computer models are all over the map (more here). According to the 10:00 AM discussion: The NOGAPS and GFDN models have made a large jump to the west over Louisiana...whereas the majority of the NHC models take Katrina inland over the northeast Gulf Coast [i.e., Alabama or the Florida panhandle]. The official forecast track remains in the right portion of the model guidance envelope. My New Orleans nervousness increases. New Orleans in peril8/26/2005 01:57:00 PM EST Posted by Brendan Loy At the risk of being alarmist, we could be 3-4 days away from an unprecedented cataclysm that could kill as many as 100,000 people in New Orleans. Such a scenario is unlikely -- the conditions would have be just right (or rather, just wrong) -- but IMHO, it's not nearly unlikely enough to feel good about things. If I were in New Orleans, I would seriously consider getting the hell out of dodge right now, just in case. Once the evacuation orders are issued, if it comes to that, it'll inevitably be an absolute madhouse, despite officials' best efforts. (More here.) Some computer models are taking Katrina on a worst-case scenario track: almost due north over the marshlands and straight into the below-sea-level city, or just to its west. If the hurricane is strong enough -- and Category 4 is looking more and more likely -- that could very possibly "flood the bowl," breaching the Lake Pontchartrain levees and "turn[ing] the city and the east bank of Jefferson Parish into a lake as much as 30 feet deep, fouled with chemicals and waste from ruined septic systems, businesses and homes... trap[ping] hundreds of thousands of people in buildings and in vehicles... [while] high winds and tornadoes...tear at everything left standing." (Source.) And, even if evacuation orders are issued, lots of people won't leave. Hence the prediction of between 25,000 and 100,000 deaths in a worst-case direct hit. I, and everyone else, had the same fear when Ivan was approaching last September. That storm ultimately took a right-hand turn and hit near the Florida/Alabama border. Georges in 1998 was also a close call, but it, too, veered right at the last minute. Will Katrina do the same? Maybe, but increasingly the computer models are suggesting not. Note the distinct westward shift in the GFS model's predicted landfall point between last night and this morning. And the GFS is not alone. According to Charles Fenwick at Eye of the Storm: Every global model plus the GFDL shifted its track to the west its forecast to the west in its 12Z run. Forecasts are now in a fairly tight cluster between eastern Louisiana and Mississippi. While it is generally unwise to hop onto one run of the models as the gospel, it is meaningful when every model makes the same type of shift. This definitely shifts the area of concern much further west than I had been figuring. CAVEAT: Hurricane forecasting is an extremely inexact science, especially when we're talking about what will happen in 72+ hours. Hence my statement that the New Orleans scenario is "unlikely." It would be statistically unlikely even if the Big Easy were directly in the center of the NHC's forecast track, because these things can, and usually do, change. That's why the highest coastal strike probability percentages at this point are under 20%. Katrina is going to hit somewhere along the Gulf Coast, but the actual odds of her taking any particular track, even the most likely one, are still quite low, because there are just so many possibilities. But despite that fact, if New Orleans is anywhere near the center of the risk area, residents need to prepare as if there is a 100% chance of a direct hit, because the 90% chance it won't happen isn't going save their lives if the 10% chance it will happens to come true. Anyway, it will be very interesting to see what the National Hurricane Center's discussion at 4:00 PM EST says. Presumably this new computer-model guidance will cause them to shift the official forecast track substantially to the west. But how far west? And how long will they wait before issuing watches and warnings? Normally, watches go up approximately 48 hours before the leading edge of the storm is expected to hit, but I wonder whether the NHC might fudge that a bit, and issue watches earlier, if New Orleans looks like the target, in light of the time-consuming logistical nightmare that a citywide evacuation would be. On the other hand, an evacuation that ultimately proves to have been unnecessary is economically costly and, more importantly, may have a vigilance-lowering "boy who cried wolf" effect, especially since it would be the second time in as many years. So this is going to be a tough call for the NHC. Here's hoping they get it right... and here's praying that New Orleans is spared. Humbled by Katrina8/26/2005 05:54:00 PM EST Posted by Brendan Loy The 4:00 PM forecast track has Hurricane Katrina aiming for Mobile Bay, which would be Apocalypse Lite -- really bad, but an order of magnitude less bad than a direct hit on New Orleans. However, the Mobile scenario is on the "east end of the guidance envelope," according to the discussion. We could easily see some further westward drift in the NHC's predicted track at 10:00 PM and 4:00 AM. Bottom line, the forecast is very much in flux, and it's far too early to know where this thing is headed. If you stop and think about it for a moment, there's something incredibly humbling about the situation we're in right now, watching and waiting to see where Katrina goes. A week from now, the city of New Orleans -- a great, industrialized city in the most powerful nation in the history of the world -- might be annihilated, or it might be devastated but not destroyed, or it might be mildly damaged, or it might be perfectly fine. We have absolutely no control over, and a very limited ability to predict, which of these scenarios will occur. We are utterly at nature's mercy. Which scenario occurs -- annihiliation, devastation, mild damage or no damage at all -- will be determined, when you boil it down to the bare essentials, by the movements of countless air and water vapor molecules through the atmosphere over the Gulf of Mexico and elsewhere. The vagaries of atmospheric dynamics will determine the fates of thousands of human beings. A miniscule variation in the upper-level pressure gradient right now could alter Katrina's track enough that, 72 hours from now, it ends up 100 miles east or west of where it otherwise would have been. That is more than enough to differentiate life from death, city from no city. Indeed, as Charles Fenwick points out, even 30 miles here or there can separate a close call from a direct hit. "The difference between absolute disaster, major damage...or annoyance is within the margin of forecast error at 12 hours." Right down to the bitter end, the air molecules control our fate. If Katrina gets close enough, a last-minute "wobble" could save, or doom, the Big Easy. If you're a religious person, I guess those atmospheric dynamics might seem a bit less random. But then, devastating natural disasters have happened before, and they'll happen again, so I'm not sure how comforting the idea of the Guiding Hand of God is in this situation. I tend to say things like "pray that New Orleans is spared" because I'm really not sure what else to say or do; prayer is the only thing that even has the potential to work. Anyway, supposing there is a God or some sort of higher power (which I firmly believe) and supposing He makes a habit of intervening in our everyday lives (of which I am far less certain), the fact remains that His decisions are just as inscrutable as the molecules' random movements, and thus it's just as humbling regardless of whose mercy we're at: nature's or God's. Either way, we do not control our own destinies nearly to the extent that we like to believe. That might sound a bit depressing, but like Casey, I find it awe-inspiring, in a way. He said it in the context of the forces that shaped the Earth billions of years ago, but it applies here too: "I find our fragility both beautiful and humbling, daunting and inspiring. We're here because this indifferent world of ours somehow worked out just right, but we're simultaneously subordinate to these cycles of destruction and (when lucky) creation that are much larger than any one species." State of emergency in Louisiana8/26/2005 09:44:00 PM EST Posted by Brendan Loy The governor of Louisiana has declared a state of emergency. Good. Residents of New Orleans and the surrounding areas need to realize now just how serious the threat from Hurricane Katrina really is. Much of the media seems convinced that this is still exclusively a Florida issue, which is just not true. Drudge's headline is "Katrina could be Cat. 4 at second Fla. strike," which is ridiculous, considering the current expected landfall is along the Alabama/Mississippi border, and that's on the eastern edge of the computer-model guidance. That's not to say a Florida landfall isn't still possible -- it certainly is -- but people need to be making preparations RIGHT NOW all along the northern Gulf coast, especially New Orleans. UPDATE: Welcome, InstaPundit readers! Scroll down for my complete coverage of Katrina. Also, click here to read about what the hurricane could do to New Orleans if she's strong enough and makes a direct hit on the city. Bottom line: tens of thousands could die. Here's a look at the computer-model guidance right now:
Remember, the worst-case scenario is "a hurricane moving in from due south of the city." And that's what the computer models are forecasting right now. Check out the GFS. My wild guess? Katrina will spare New Orleans -- making landfall west of the city, over the central parishes (a la Andrew). Models "cluster" on near-worst-case track8/26/2005 09:56:00 PM EST Posted by Brendan Loy The 10:00 PM discussion of Hurricane Katrina is pretty much all bad news. Let's start with the new forecast track, which has once against shifted to the left, and is now very, very close to being the doomsday scenario for New Orleans:
Here's a closer view. This is pretty much the very track that disaster planners have feared for years, the one that features a major hurricane "moving in from due south of the city" with the eye passing "next to New Orleans but just to the east," thus literally blowing the overflowing Lake Pontchartrain into the city, turning the Big Easy into a modern-day Atlantis. (Here's what it might look like. Here are some maps.) Here's my (entirely unofficial) rendering of a close-up of the NHC's track, using Google Maps, and based on the forecast latitude and longitude points for 48 and 72 hours (and a conservative estimate of recurvature):
Compare and contrast with Camille and Betsy, both of which were further from New Orleans than this would be. This is not good, people. And it gets worse: It is worth noting that the guidance spread has decreased and most of the reliable numerical model tracks are now clustered between the eastern coast of Louisiana and the coast of Mississippi. This clustering increases the confidence in the forecast. Great... a high-confidence forecast for a track that could kill 100,000 people and utterly destroy a major American city. Oh, and another bad thing: after leveling off this afternoon and evening, Katrina is strengthening again. She's up to 105 mph now. The official forecast brings her to 130 mph at landfall, with 160 mph gusts. One computer model thinks she'll have sustained winds of 140 mph. Another says 150 mph. Barring some unexpected intervening force, this thing is going to be a monster. The water out there is very warm and very deep, and the atmosphere is very conducive to strengthening. There's nothing standing in Katrina's way except, well, the Gulf Coast. I expect Hurricane Watches and massive evacuations tomorrow. If I can glean any good news out of this discussion, it might be this: "Katrina continues to move stubbornly toward the west-southwest or 250 degrees at 7 knots along the eastern side of a very strong deep-layer mean high centered over Texas." I like that word "stubbornly," because when hurricanes are moving "stubbornly," it often means the forecasts will continue to be wrong because the computer models really are not understanding the dynamics of what's going on. In this case, that might mean Katrina will continue to move further west than expected, and perhaps New Orleans will be spared as landfall occurs west of the city, in the central parishes. This is actually my personal forecast, but bear in mind, I'm not a meteorologist, I just play one on the Internet. Bottom line... New Orleans is in serious trouble if Katrina follows the NHC's projected path. CAVEAT: Hurricane forecasting is an inexact science. 72-hour predictions have a substantial margin of error. The entire northern Gulf Coast should be keeping a very close eye on Katrina. I am focusing on New Orleans because a direct hit there would be catastrophic in a way that no other scenario would be, NOT because other areas are safe. If you live anywhere from western Louisiana to the central Florida panhandle, you should be watching Katrina closely. P.S. Charles Fenwick writes: "Residents of coastal southeast Louisana, Mississippi, and western Alabama need to start taking action tomorrow morning to prepare for the arrival of what will be a dangerous hurricane. Due to the warming of the Gulf of Mexico that has taken place throughout the summer, there is far more fuel for the hurricane as it approaches the coast. Dennis ran out of gas as it were during his last hours [over the water]. This is much less likely to be the case for Katrina as deep warm waters extend almost all the way to land." Evacuate8/26/2005 11:22:00 PM EST Posted by Brendan Loy I'm not a meteorologist. I'm just an amateur weather enthusiast, a law-student blogger who happens to be a hurricane buff. But if I lived in New Orleans, I would definitely leave at this point. Tonight. Barring a major change in the forecast, I expect the evacuation orders to come tomorrow. That will produce massive traffic jams and general confusion. My advice? Beat the rush; get out now. For it is imperative to get out. Katrina probably won't destroy New Orleans -- but it could. So if anyone in New Orleans is reading this, I'd personally advise you to get the hell out of dodge. The Big One?8/27/2005 01:00:00 AM EST Posted by Brendan Loy Here's an excellent essay, written in 2002, about the mortal threat that New Orleans faces. If you live in New Orleans, here is the official evacuation info from the Louisiana State Police that you'll probably be needing tomorrow. If there's a storm surge into Lake Pontchartrain, this storm-surge gauge (located here) will see it, as will these water-level monitors: 1, 2, 3. (More data here and here.) Finally, here are some traffic cams from the New Orleans area. Could get interesting tomorrow. UPDATE: I just got an e-mail report from Tom Grace, a resident of Metairie, LA, just west of New Orleans. He writes: I just got back from tieing up my boat, putting out extra lines and fenders, and generally preparing her as best I could for Katrina, in case she comes here. We are in the process of putting things together to load into the car, so we can leave in the morning. We have reservations in Memphis, the closest place we could find a pet-friendly hotel. Wish us luck. We will need it. Our press reports that because of the gradual destruction of the barrier islands, which used to provide protection for us, our city now faces extreme danger from even a Category 2 storm. In the past it was believed that we faced that danger only from a Category 3 or stronger storm. See, for example: [here and here]. More later, if we get a chance. Good luck, Tom and family. And thanks for the e-mail. 110 mph8/27/2005 02:28:00 AM EST Posted by Brendan Loy Hurricane Katrina now has maximum sustained winds of 110 mph, putting her on the threshold of Category 3. I'm going to bed now; by the time I wake up, I expect her to be a major hurricane. Katrina a Cat. 3; expected to be 145+ mph at landfall8/27/2005 12:58:00 PM EST Posted by Brendan Loy Katrina officially became a major hurricane overnight, with 115 mph winds, and her expected intensity at landfall was upped to 145 mph. Moreover, according to the 10:00 AM discussion, "IT IS NOT OUT OF THE QUESTION THAT KATRINA COULD REACH CATEGORY 5 STATUS AT SOME POINT BEFORE LANDFALL." Also at 10:00 AM, the NHC issued a Hurricane Watch for southeastern Louisiana, including New Orleans and Lake Ponchartrain.
"This is not a test," said New Orleans mayor Ray Nagin. Evacuation orders for the city will be issued very soon. Already, nearby Placquemines and St. Bernard parishes have urged people to leave. ("According to the state's plan, New Orleans and Orleans Parish call for evacuations after the low-lying areas to allow people who live south and east of the city to get on the road first and head for safety.") Mayor Nagin urged New Orleanians to "get their supplies, get their medications in order, clean up storm drains and get ready. Because it looks as if we're going to get hit." The Hurricane Center will likely expand the Hurricane Watches eastward, to cover the Mississippi and perhaps Alabama coastlines as well, later today. It sounds like they did follow my advice and fudge the normal timetable a bit for New Orleans, where hurricane preparedness is a uniquely difficult prospect. It bears repeating just what we're dealing with here: the potential destruction of a city, and the deaths of many thousands who are unable or unwilling to evacuate. Dr. Jeff Masters puts the odds of this scenario at one in ten: 'd hate to be an Emergency Management official in New Orleans right now. Katrina is pretty much following the NHC forecast, and appears likely to pass VERY close to New Orleans. I'm surprised they haven't ordered an evacuation of the city yet. While the odds of a catastropic hit that would completely flood the city of New Orleans are probably 10%, that is way too high in my opinion to justify leaving the people in the city. If I lived in the city, I would evactuate NOW! There is a very good reason that the Coroner's office in New Orleans keeps 10,000 body bags on hand. The risks are too great from this storm, and a weekend away from the city would be nice anyway, right? GO! New Orleans needs a full 72 hours to evacuate, and landfall is already less than 72 hours away. Get out now and beat the rush. You're not going to have to go to work or school on Monday anyway. If an evacuation is ordered, not everyone who wants to get out may be able to do so--particularly the 60,000 poor people with no cars. And it only gets worse. In addition to increasing in strength, Katrina has also substantially increased in size, as you can see for yourself here. Hurricane-force winds now extend outward up to 40 miles, and tropical-storm-force winds up to 150 miles, from the center; that's up from 25 and 85 miles, respectively, just 12 hours ago. Katrina "will deliver a widespread damaging blow wherever she comes ashore," says Dr. Masters. Okay, now for the good news, such as it is. Katrina hasn't strengthened since she reached 115 mph about eight hours ago. She's been going through an eyewall replacement cycle, and it's possible she might weaken a bit this afternoon (though I'm not sure if that's good or bad news, as it might cause people to become dangerously complacent, only to have Katrina blow up into a monster tomorrow). Also, according to the discussion, "There is a possibility that southerly or southwesterly shear could affect Katrina starting at 48 hr...and as always happens in hurricane of this intensity additional concentric eyewall cycles could occur." That would be good... although, 48 hours from now, she'll already have come ashore, won't she? Hmm... HURRY UP, SHEAR!!! Those two things -- wind shear and eyewall replacement cycles -- are the only factors that might prevent Katrina from being another Charley, or worse, another Camille, at landfall. Water temperatures aren't going to do the trick, as they did with Opal and Dennis. The sea-surface temperatures near the shoreline have warmed since July, there's a patch of water due south of New Orleans that is extremely warm and deep; that could easily be the engine that boosts Katrina to Cat. 5 during the final hours before landfall. Which, of course, would be very, very, very bad. Katrina: a critical moment8/27/2005 02:20:00 PM EST Posted by Brendan Loy We're at a critical moment in Hurricane Katrina's development right now. The next few hours are probably the last, best chance for a serious disruption that could ultimately prevent Katrina from making landfall as a monster hurricane. Weatherblogger Steve Gregory explains: Katrina is currently in a presumably temporary weakening cycle due to an eye wall replacement that began 5 hours ago ... In all likelihood, Katrina's max winds at the surface are now of only CAT 2 intensity. ... Katrina will complete the eye wall replacement cycle, and the eye will again begin to shrink down by this evening ... NOTE: Katrina's eye wall cycling, that has resulted in a 50NM wide eye, leaves Katrina in a 'vulnerable' state -- and dry air intrusion could take place during the next 6 hours which will trash the intensity forecast. Until this evening, we really won't know for sure. ... [T]here will be a period of time on Sunday when the shears will approach zero, and, the outflow to the NNW of the storm will be enhanced by the high level, southwesterly winds ahead of the developing TROF. This 12-18 hour period of 'perfect' environmental conditions and winds, including even warmer waters associated with the loop current, and the semi-permanent 'pool' of warm water in the Gulf south of Louisiana -- will provide ideal conditions and the opportunity for Katrina to rapidly intensify, and the ability to attain strong CAT 4 if not CAT 5 intensity (assuming she manages to re-intensify this evening!) So, what happens in the next six hours or so is absolutely critical. Hopefully some dry air will get in there and mess things up. Tulane closes8/27/2005 02:36:00 PM EST Posted by Brendan Loy Tulane University, in New Orleans, is closing at 5:00 PM today. The dorms are closing until Wednesday. Classes are cancelled until Thursday. Orientation is cancelled. Everything is shutting down. Everyone is being told to leave: New first-year students who are
arriving on campus today should make plans to leave campus as soon as
possible. No students will be allowed to occupy residence halls after 6 p.m. today. Traffic moving north of N.O.8/27/2005 02:50:00 PM EST Posted by Brendan Loy I just talked to Tom Grace, the blog reader who e-mailed me last night saying he and his family would be leaving New Orleans this morning. They are indeed on the road, halfway to Jackson, MS. (Their destination is Memphis.) He said there's moderate traffic, moving at 65 mph. He's going to call back later, when he's off the road, so I can give him the necessary information so he can file audioblog reports. Here's what he e-mailed me a few hours ago, before leaving: We have the house almost buttoned up and the car half packed. We will be leaving New Orleans within a couple of hours. Have to pick up my 87 y.o. mom, then head North, across Lake Pontchartrain, where we will meet up with my wife's family before taking I-12 to Memphis. At the moment, we are planning to take both cars, though we may leave one of them on the North Shore, in Covington, LA, which might be a safe place for it. ... I just want to leave early, before "the lemmings" as I call them. Most people will decide to leave about the same time, then it could take 10 hours to get 30 miles, as it did for my son and his family last year when they waited just a few hours to evacuate for Hurricane Ivan. Anyone else in Katrina's path -- or in the process of evacuating from it -- please feel free to e-mail me if you'd like to file some first-hand reports, either by audio, or if you have a camera phone, or whatever. Memo to New Orleanians who are thinking about "riding it out"8/27/2005 03:46:00 PM EST Posted by Brendan Loy Dr. Jeff Masters puts the odds of a catastrophic "filling the bowl" scenario -- i.e., the destruction of New Orleans -- at approximately 10 percent. So here's the question you should be asking yourself, if you live in the Big Easy (or anywhere inside the "bowl") and are hesitant to evacuate: If you knew there was a 10 percent chance terrorists were going to set off a nuclear bomb in your city on Monday, would you stick around, or would you evacuate? That's essentially equivalent to what you're dealing with here. I sure as hell would leave. Watches extended east, track inches west; Warnings tonight8/27/2005 06:53:00 PM EST Posted by Brendan Loy Sorry for the lack of updates. I had a headache earlier and needed to rest. That turned into a three-hour nap. Luckily (or unluckily, for New Orleanians), not much changed while I was asleep. Katrina is still at 115 mph; she's still in a concentric eyewall cycle, but seems to certain to strengthen once it's over; and the forecast track still looks like a worst-case, potential doomsday scenario for New Orleans. Katrina's sustained winds are still expected to reach 145 mph at landfall, with gusts to 180 mph, and it is still possible that she'll get even stronger than that, becoming just the fourth Category Five hurricane in recorded history to make landfall on the United States mainland. Hurricane Watches, as expected, have been extended eastward to the Alabama/Florida border, but that doesn't indicate an rightward lurch in the track; the NHC simply put the Louisiana warnings up a few hours early, to give New Orleans and vicinity more time to prepare. The track has actually edged ever-so-slightly to the left, but the below-sea-level city of New Orleans is still directly in the crosshairs. For some reason that I can't even begin to comprehend, the evacuation order for New Orleans is only "voluntary" at this time. The mayor says he might issue mandatory evacuations tomorrow morning, depending on what the forecast says. What is he waiting for??? The forecast calls for a DIRECT HIT! This is the story we've been fearing for decades! And if he waits until 24 hours before landfall to order people to leave, it may very well be too late! People getting stuck on the highways while a Category Five hurricane makes landfall is one of the most horrifying scenarios imaginable!!! The mayor of New Orleans is an idiot8/27/2005 07:34:00 PM EST Posted by Brendan Loy I can't emphasize enough what a bad decision I think it is for New Orleans Mayor Ray Nagin to delay the mandatory evacuation order until tomorrow morning. According to the Weather Channel, lots of tourists in the French Quarter are happy the evacuation is only "voluntary," and are planning to stay in town until it becomes mandatory. Idiots. Those people may find themselves stuck on a highway with 180 mph wind gusts howling around them. (Of course, if that happens, they won't actually be "stuck" for long. Nor will they be on the highway.) Landfall is expected to occur around midday Monday. So by waiting until tomorrow morning, Mayor Nagin will be giving people scarcely 24 hours to get out. Perhaps he's hoping to ease the evacuation traffic jams by starting things off with a trickle, but that's awfully risky. Will Ray Nagin go down in history as the mayor who fiddled while New Orleans drowned? Could be. Tell it like it is, Jim8/27/2005 07:54:00 PM EST Posted by Brendan Loy Watching the Weather Channel... Jeff Morrow is in New Orleans. Stephanie Abrams is in Gulf Shores, Alabama. Jim Cantore is in Biloxi, Mississippi, trying to position himself to be in the heart of the right-front quadrant, or as he calls it, "home." :) Cantore seems to be the only person on the The Weather Channel who is willing to utter the dread words "Category Five." Good for him. People along the coast need to realize exactly what they're dealing with here. There is a substantial chance that this could be not just another Ivan, not just another Betsy, but another Camille. Will hearing that scare people? Yes, and that's good! The important thing here is not to prevent panic. It's to cause just enough panic to convince people to LEAVE. Katrina strengthening again8/27/2005 07:56:00 PM EST Posted by Brendan Loy
The barometric pressure is dropping again: 10:00 AM: 940 mb The wind speeds often take a number of hours to "catch up" with the pressure. Katrina never reached its full potential as a 940 mb hurricane prior to the eyewall replacement cycle (which, I think, is why the winds never dropped below 115 mph, even as the pressure rose). So now that the pressure is back down in the 940 mb range, I expect it won't be long before the winds start ramping up. Another Camille?8/27/2005 08:15:00 PM EST Posted by Brendan Loy Because no one else seems willing to say this, I'm going to keep screaming it until my face turns blue: Katrina could be another Camille. Meteorology student Charles Fenwick of Eye of the Storm explains why: If you were writing a book on hurricanes and wanted to get examples of the factors needed to create a category five hurricane, you would not have to search hard. For all exist right now. Low shear? Doesn't get lower than this (parts of Katrina are in areas of sub-5 knot shear). High amounts of heat potential? Red freaking hot, right in the middle of Katrina's path. A well-organized, already powerful hurricane? Here you go. Can I guarantee a category five? No. Is Katrina going to try her damndest to make it? Yes. The only things limiting her are space, time and the sole weakness of a powerful hurricane: An unpredictable eyewall replacement cycle that temporarily reduces its strength. One eyewall replacement cycle is ending. Now Katrina has probably a solid day of intensification ahead. I expect to see some amazing pressure drops overnight tonight and/or tomorrow. A well-timed second eyewall replacement cycle, occurring shortly before landfall (but not too long before, because then it will have time to restrengthen), now appears to be the only thing that can the Gulf coast from a calamity significantly worse than any of the recent hurricanes that have struck there. And there is no guarantee that such a lucky event will occur. If you think you can ride out Katrina because you survived Ivan and Dennis, you're wrong. You need leave, and you need to do it now, before it's too late. As Fenwick writes: If you are living on the coast or an otherwise low-lying area inside the danger cone portrayed in the National Hurricane Center forecast and you do not have plans to leave, then you are putting your life in grave danger. ... There is still time to secure life and property, but it is quickly running out. For the residents of the northern gulf coast, now is the time to take decisive action to do both. Steve Gregory also has an excellent post about eyewall replacement cycles and what's going on with Katrina. Katrina could cost $100 billion, spike oil prices to $75/barrel8/27/2005 08:57:00 PM EST Posted by Brendan Loy On top of everything else, Hurricane Katrina could be economically devastating, costing the insurance industry countless billions and sending gas prices even higher than they already are. Let's start with the latter issue. Steve Gregory writes: Hurricane Katrina is heading for 'Prime Oil Producing Real Estate' in the north central Gulf. Unless the forecasts prove very wrong (as in landfall 250 miles to the east, or the storm is much weaker) -- Oil prices will jump tremendously on Monday. Last year IVAN took out fully 6% of the entire U.S. annual production of oil and a fair amount of this year's record high prices has to do with the 'threat' of another IVAN. On Friday, the 'market thought' Katrina would be a CAT 2 in the Florida Panhandle - and priced oil accordingly. If Katrina 'stays on course', prices will jump $3-$5 per barrel Monday morning. Further increases to $75/bbl may follow Tuesday if there are reports of serious infrastructure damage on par with that done last year by IVAN - by far the most expensive hurricane to affect the U.S. oil producing industry. As far as the potential for direct costs from hurricane damage, Dr. Jeff Masters says Katrina could be the "costliest hurricane ever" if she hits New Orleans as a Category 4 hurricane: Insurers estimate that Katrina already did about $1 to $4 billion in damage (total damage is roughly double insured damage). This is a shocking number for a Category 1 hurricane, and bodes ill for the residents of New Orleans and the U.S. insurance industry if Katrina makes a direct hit on New Orleans as a Category 4 storm, which would likely cost $100 billion. But, New Orleans' amazing run of luck could well continue at the expense of Mississippi or Alabama or Florida. Like Camille in 1969, Katrina may come ashore far enough east of New Orleans to largely spare it. Only time, and eyewall replacement cycles, will tell. Dr. Jeff Masters: 20% chance of New Orleans calamity8/27/2005 08:59:00 PM EST Posted by Brendan Loy The weatherbloggers are kicking into high gear. Dr. Jeff Masters has another excellent post: We may be on the verge of a rapid deepening phase, since the shear and dry air on the northwest side of the hurricane appear to be lessening, and the hurricane is moving over a deep layer of warm water of almost 90F. The areal size of the hurricane continues to expand, and Katrina is growing from a medium sized hurricane to a large hurricane. Where the pressure will bottom out after this deepening phase is anyone's guess, and I believe something in the 915 - 925 mb range is most likely [Hurricane Andrew was 922 mb at landfall; Camille was 909 mb. -ed.], which would make Katrina a strong Category 4 or weak Category 5 hurricane by tomorrow afternoon. The deepening phase may last longer than usual for a major hurricane, since Katrina is expanding in size and thus has more mass to spin up. After this phase of rapid deepening, another eyewall replacement cycle will occur, and the timing of that cycle will be worth billions of dollars and perhaps many lives. There is no way to predict when this eyewall replacement cycle will occur. Another major factor will be the timing of the tides--if Katrina hits at high tide, there will be billions more in damage. There is still the possibility, too, that the trough that is now steering Katrina to the north will also create enough shear to reduce her to a Category 3 storm at landfall. This is what happened to Hurricane Ivan last year. New Orleans finally got serious and ordered an evacuation, but far too late. [Actually, they didn't even "order" it, they merely suggested it. -ed.] There is no way everyone will be able to get out of the city in time, and they may be forced to take shelter in the Superdome, which is above sea level. If Katrina makes a direct hit on New Orleans as a Category 4 hurricane, the levees protecting the city will be breached, and New Orleans, which is 6 - 10 feet below sea level, will fill with water. On top of this 6 feet of water will come a 15 foot storm surge, and on top of that will be 20 foot waves, so the potential for high loss of life is great. Given the current track and intensity forecast, I'd put the odds of this at about 20%. How to not get caught on the highway during a major hurricane 1018/27/2005 09:25:00 PM EST Posted by Brendan Loy Traffic isn't terribly bad on the roads leading out of New Orleans right now, according to Jeff Morrow on The Weather Channel. Specifically, he says the road to Baton Rouge is pretty clear. So now is still a good time to evacuate. When the idiot mayor finally announces the mandatory evacuation order tomorrow morning, that will change. Hurricane Warnings up; barometric pressure down8/27/2005 09:52:00 PM EST Posted by Brendan Loy Hurricane Katrina's minimum central pressure is down to 939 mb -- that's the lowest it's been yet, and it corresponds to Category 4 strength. But it may take the winds a few hours to "catch up" with the pressure, especially given Katrina's newfound huge geographic size. Officially, the winds are still at low-end Category 3 strength, or 115 mph. I think that will change by the 4:00 AM advisory, and certainly by the 10:00 AM advisory I expect Katrina will be a Category 4 hurricane (131 mph+). I wouldn't be at all surprised if she's a high-end Category 4 or even a Category 5 by afternoon or evening. All the conditions for rapid intensification are there; now it's just a matter of watching and waiting to see if it happens, or perhaps more precisely, how bad it is. Meanwhile, most of the Hurricane Watches have been upgraded to Hurricane Warnings.
(The blue-and-pink zones on the far east and far west are Hurricane Watches and Tropical Storm Warnings; the red area is under a Hurricane Warning.) "This one is different"8/27/2005 10:08:00 PM EST Posted by Brendan Loy Axodys has a good round-up of New Orleans bloggers' posts. My favorite is this: Dear Evacuation Monkeys: This one is different. You officially have my permission to freak out. Heh. Indeed. |
