TD13 has regenerated and was upgraded to TS Lee today at 21Z. However, it does not look very healthy and will likely be back down to a TD in 2-3 days. It's located at 30.5N 49.7W and heading NNE at 12kts. The intensity estimated by satellite is 35kts and 1007mb.
The strong tropical wave 1200 miles east of the Lesser Antilles is STILL looking impressive, with an obvious surface circulation and persistent deep convection. This is the wave that exited Africa on August 27. I honestly don't know why this is not being classified as TD14 yet, but from my experience, it should be. It's presently at about 19N 42W and heading NW at 10kts. The next name on deck is Maria.
And lastly, a new tropical wave has exited Africa and is already showing signs of a broad circulation. This will be watched closely for signs of development over the next few days.
The NTC as of the end of the month is now 110.2%, compared to a normal 31% or so for this date. Recall that a value of 100% corresponds to an entire average season. So 2005 is already 10% above an entire normal season, and the climatologically active part of the season is still ahead of us.
Please visit my tropical Atlantic headquarters.
30 August 2005
36 hours after landfall, the people in New Orleans emergency shelters are being evacuated as levee after levee is breached by flood waters and the shelters are filling with water. Water from the Mississippi River and from Lake Pontchartrain is now pouring into the city, bringing the water level up to at least 25 feet in parts of the city. Also, as time goes by, we start to get more reports from the coast of Mississippi and realize how complete and extensive the destruction really is. Gulfport and Biloxi are in very bad shape to say the least, and strong tornadoes generated by Katrina's spiral bands have ravaged parts of Georgia. This is very similar to Hurricane Camille in 1969, but Katrina was LARGER. The death toll from the storm is now around 70, but there are a LOT of people unaccounted for, so that number could rise drastically in the coming days and weeks. Nearly all communication and transportation is cut off, so information out of the area and assistance into the area are greatly hindered. I'll once again provide a link to the American Red Cross for donations: https://www.redcross.org/donate/donation-form.asp. Although Gulfport was hit very hard by the eastern eyewall, New Orleans may end up being the worst off, as the city sits submerged for weeks or even months without power, water, or sewer services. The ultimate doomsday forecast that was made for the city has sadly come to fruition. The terrorist attacks on the US in 2001 had a total cost of about $40 billion. Hurricane Andrew in 1992 cost $42 billion. All four big hurricanes in 2004 (Charley, Frances, Jeanne, and Ivan) added up to about $46 billion. Hurricane Katrina could potentially be twice those values. For those who are interested, I have created radar loops of Katrina's two landfalls: the first on Thursday afternoon near Miami, and the second on Monday morning near New Orleans. http://einstein.atmos.colostate.edu/~mcnoldy/tropics/katrina/Katrina_25Aug05.gif http://einstein.atmos.colostate.edu/~mcnoldy/tropics/katrina/Katrina_29Aug05.gif The tropical wave I mentioned yesterday over the central Atlantic between Africa and the Lesser Antilles has remained unchanged. There is still a disorganized broad surface circulation and a more impressive anticyclone aloft. It's located roughly at 14N 38W and tracking W at 10kts. Conditions still appear favorable for gradual development.Please visit my tropical Atlantic headquarters.
Posted by at 6:53 PM
29 August 2005
At about 11Z today, Katrina made landfall on the Mississippi River delta in southeast LA as a potent CAT4 hurricane. Maximum sustained winds were estimated to be 120kts with a MSLP of 920mb. Then it proceded north... the western eyewall hitting New Orleans, and the eastern eyewall hitting Gulfport and Biloxi. There are already reports of significant flooding and damage all along the coast in LA, MS, and AL -- from New Orleans to Pensacola. It's still too early to get a complete picture of what has transpired this morning, but it will be an extremely costly disaster. Cities as far east as Mobile, AL had levees topped and flood waters racing into the city. Buoys just offshore reported waves of 40+ ft ahead of the storm. The storm has since moved inland and weakened to a CAT1 hurricane as of this writing. Further weakening will occur, but now the primary threat is from inland flooding, and that is a risk for the next several days in the southeast and Ohio Valley. Visit http://www.spc.noaa.gov/products/wwa/ to check out the most current watches and warnings. Remember that tornadoes and flash floods are big dangers from hurricanes that have made landfall... even quite far from where it made landfall. As of 19Z, Hurricane Katrina was located at 31.4N 89.6W (near Hattiesburg, MS) and tracking N at 15kts. The intensity is 80kts and the MSLP is 955mb. On its forecast track, it will be passing over TN, KY, and OH over the next couple of days. If you wish to help the Katrina victims, the American Red Cross has a donation form at https://www.redcross.org/donate/donation-form.asp Due to excessive shear in the critical formative stage, TD13 has dissipated into an open wave and is no longer forecast to intensify. It will be watched for signs of regeneration though. However, a relatively new wave has exited the African coast and is located near 10N 32W, just southwest of the Cape Verde Islands. It shows signs of development and conditions should be favorable for gradual organization.Please visit my tropical Atlantic headquarters.
Posted by at 3:28 PM
28 August 2005
Since my last update on Friday, Katrina has done the unimaginable, and rapidly intensified to a monstrous Category 5 hurricane right off the US coast. To make matters more dire, it is headed for one of the most vulnerable cities in the US: New Orleans. The storm experienced a phenomenal period of rapid intensification, with pressure drops of 27 mb/3hr and 36 mb/12hr. As of this writing, the storm is STILL strengthening, currently holding the 4th lowest pressure ever recorded in the Atlantic. As of 21Z today, aircraft recon found maximum sustained winds of 145kts and a minimum central pressure of 902mb. It is located at 26.9N 89.0W and tracking NW at 10kts. This puts it 225 miles south of New Orleans. It is forecast to gradually turn more to the north and maintain CAT 4/5 intensity, with fluctuations primarily due to concentric eyewall cycles. The best estimate for time of landfall is around 5am CDT on Monday. As an aside, this makes the first time there have been 3 CAT5s in 3 consecutive years (Isabel '03, Ivan '04, and Katrina '05). A mandatory evacuation has been ordered for all of New Orleans, as well as some other coastal cities in LA and MS. The storm surge from this hurricane could reach 25-30 feet, with wind gusts to 200mph or even higher. I wanted to share an excerpt from the forecast discussion out of the New Orleans NWS office:
"MOST OF THE AREA WILL BE UNINHABITABLE FOR WEEKS...PERHAPS LONGER.
AT LEAST ONE HALF OF WELL CONSTRUCTED HOMES WILL HAVE ROOF AND WALL
FAILURE. ALL GABLED ROOFS WILL FAIL...LEAVING THOSE HOMES SEVERELY
DAMAGED OR DESTROYED. POWER OUTAGES WILL LAST FOR WEEKS...AS MOST
POWER POLES WILL BE DOWN AND TRANSFORMERS DESTROYED. WATER SHORTAGES
WILL MAKE HUMAN SUFFERING INCREDIBLE BY MODERN STANDARDS."
The President has already declared Lousiana and Mississippi federal disaster areas to expedite funding and recovery efforts once the storm passes. A Hurricane Warning is in effect from western LA to the FL panhandle. Aside from the devastating eyewall, areas to the east of landfall can expect
VERY large waves, perhaps upwards of 40 feet, along with 1-2 feet of rain. Elsewhere, TD13 has formed from the area of disturbed weather in the deep tropics between the Lesser Antilles and Africa. It is located at 15.4N 46.8W. Initial intensity is estimated to be 25kts and 1007mb. This is from a wave that exited Africa on August 25. The longer range forecast for this is to head northwest (north of the Leeward Islands) and gradually strengthen to hurricane intensity by later this week. This should be upgraded to TS Lee sometime tomorrow.
Please visit my tropical Atlantic headquarters.
Posted by at 5:03 PM
26 August 2005
At about 23Z yesterday, Katrina made landfall as a CAT1 hurricane on North Miami Beach, FL. The storm was highly asymmetric, and nearly all of the rainfall occurred on the south side, quite extreme in some places. Wind gusts to nearly 85kts were observed at several places, and radar-estimated rainfall totals in southern FL are 10-20" along the south side of the track. So far, this hurricane has killed 4 people, and left 5 missing at sea. The hurricane barely noticed that it was over land, since the land is flat and mostly swampy. Then, a peculiar turn to the southwest allowed the storm to spend just 7 hours over the peninsula before exiting into the Gulf. It responded well to the transition and is now strengthening very quickly. The pressure at first landfall was 985mb, and shortly after landfall was 971mb (usually is the other way around!). Conditions over the Gulf are ideal for rapid intensification -- the SSTs will remain above 30C and the northerly shear that has been affecting it is expected to relax. At 15Z today, the center of Hurricane Katrina was located at 25.1N 82.2W and crawling W at 6kts. Intensity measured by aircraft is 85kts and 971mb, making it a CAT2 storm. The forecast is for continued strengthening, reaching at least CAT3 by the end of the weekend, and then hitting the FL panhandle (perhaps between Pensacola and Panama City) on Monday morning. Ahh, the Sunshine State... Elsewhere, the same circulation and area of disturbed weather I've mentioned lately in the deep tropics east of the Lesser Antilles struggles to get organized (it exited Africa on Aug 19). It still has persistent deep convection, but it is still well separated from the low-level center. It's located at about 20N 46W.Please visit my tropical Atlantic headquarters.
Posted by at 11:48 AM
25 August 2005
The storm has gradually intensified and slowed down, now moving west at just 5kts, with further slowing expected prior to landfall. That should put the eyewall ashore around 10pm EDT, probably at or near Fort Lauderdale, FL (it would be their first direct hit since 1964). It's crossing over the Florida Current, a channel in the ocean floor with a constant re-supply of warm water (30.5C+). Based on experience and some objective models, there still exists a decent chance of rapid intensification in the next few hours before the eyewall hits land. A competing factor seems to be some dry air on the north and west sides of the storm. A buoy just east of Cape Canaveral is now reporting 9ft waves, and growing rapidly (their normal non-storm wave height is about 1.5ft). The core is still far enough from land (40 miles or so) that the strong winds have not reached Fort Lauderdale as of this writing... they are currently reporting sustained winds of 15kts, gusting to 25kts. At 16Z today, TS Katrina was located at 26.2N 79.4W and tracking W at 5kts. It is being monitored constantly by aircraft and by ground-based radar, and the latest intensity is 55kts and 990mb (fell 7mb in 2 hours). A Hurricane Warning is in effect for all of the southeastern FL peninsula, and a Tropical Storm Watch is in effect for the Keys and the southwestern FL peninsula. I suspect the central FL panhandle will have a hurricane watch issued later today or early tomorrow for them. Another interesting question is, what happens after tonight's landfall? Although there is rather large divergence among model forecasts, the NHC shows the storm crossing westward over the peninsula, exiting into the Gulf, then recurving to the north and hitting the central FL panhandle early Monday morning as a hurricane. Again, there is the chance it could be rather intense if it has the time.Please visit my tropical Atlantic headquarters.
Posted by at 1:59 PM
23 August 2005
As expected, TS Jose made landfall on the Mexican coast and has since weakened considerably inland. Of much greater concern is TD12. Although one can make a very strong case for it being the remnants of TD10, the NHC called it TD12... it was upgraded to a Depression this afternoon based on an aircraft recon flight into it. The center is not exactly easy to find, as there appears to be at least a couple of them. However, the convection is very intense, the SSTs are incredibly warm, and the vertical shear is minimal. This will likely be upgraded to TS Katrina in the next 12-18 hours. At 21Z, TD12 was located at 23.2N 75.5W and tracking NW at 7kts. The maximum sustained winds are 30kts and the MSLP is 1007mb. This motion is expected to continue for a couple days, then turn west as a ridge builds to its north. What this means is that it should turn directly into the southern tip of Florida as it intensifies. Then, after crossing the tip of the peninsula, it should enter the Gulf and be under ideal conditions for rapid intensification. If you're in FL or along the northern Gulf coast, be sure to check out the track forecast! This is a small system, and has the ability intensify very quickly. Further east, the large circulation I've been mentioning is still out there at about 18N 37W, but the convection is all displaced east of the low-level center. It's seemingly very close to being upgraded to TD13 if the convection persists.Please visit my tropical Atlantic headquarters.
Posted by at 6:36 PM
22 August 2005
From what I can tell, the wave that was ahead (west) of ex-TD10 crossed the Yucatan Peninsula last night and emerged over the Bay of Campeche this morning. It very promptly organized and was upgraded to TD11. Over the next few hours, it continued to organize and intensify, and an aircraft recon flight into it found that it was indeed a tropical storm, and was upgraded to TS Jose this afternoon... the earliest 10th named storm ever in the Atlantic (by one day). At 22Z, TS Jose was located at 19.6N 95.4W and tracking W at 5kts. Intensity measured by aircraft was 45kts and 1002mb. It should make landfall on Mexico later this evening as a tropical storm and then rapidly deteriorate inland. The remnants of TD10 are still easily trackable, now near Hispaniola. The wave is very weak, but still has sporadic convection and nice curvature in visible satellite imagery. It will continue to be monitored closely, because it's heading for Florida, so IF it regenerates, things could get interesting. Elsewhere, a very large wave exited Africa on August 20, and is now at about 16N 34W. It's a bit far north for the classic track across the deep tropics, so if it forms, would likely recurve somewhere in the central Atlantic. It's also lacking deep convection at this time, but conditions should remain favorable in the foreseeable future and this could become TD12 in the next couple of days. The next name on deck is Katrina.Please visit my tropical Atlantic headquarters.
Posted by at 6:21 PM
From Gary Padgett:
Back in July I looked up the earliest occurrences of Atlantic
TCs number 6 - 12 within a season. Dennis, Emily, Franklin,
Gert, Harvey and Irene all set new records for the earliest
4th, 5th, 6th, 7th, 8th and 9th tropical storms, respectively.
Following is an updated table for TCs 10 - 21:
Number Number of Earliest 2nd Earliest 3rd Earliest
of TS Occurrences
10th TS many 23 Aug 1995 (Jerry) 26 Aug 1933 28 Aug 1936
11th TS many 28 Aug 1933 28 Aug 1936 28 Aug 1995 (Karen)
12th TS many 29 Aug 1995 (Luis) 31 Aug 1933 7 Sep 1936
13th TS 17 8 Sep 1933 8 Sep 1936 13 Sep 1995 (Marilyn)
14th TS 13 10 Sep 1933 10 Sep 1936 27 Sep 1995 (Noel)
15th TS 7 16 Sep 1933 19 Sep 1936 30 Sep 1995 (Opal)
16th TS 6 27 Sep 1933 5 Oct 1995 (Pablo) 9 Oct 1936
17th TS 4 28 Sep 1933 9 Oct 1995 (Roxanne) 21 Nov 1969 (Martha)
18th TS 3 1 Oct 1933 21 Oct 1995 (Sebastien) 4 Dec 1887
19th TS 3 25 Oct 1933 27 Oct 1995 (Tanya) 7 Dec 1887
20th TS 1 26 Oct 1933
21st TS 1 15 Nov 1933
All the above is based on the current Best Track file, which has been re-analyzed for the
years 1851 - 1910. Information for 1911 onward will be subject to revision, and this
could affect stats for some of the busier seasons, especially 1916, 1933 and 1936.
Posted by at 10:26 AM
17 August 2005
Since my last update two days ago, Irene had briefly reached Category 2 intensity, but is now rapidly losing tropical characteristics as it is affected by the mid-latitude jet. It has been downgraded to a Tropical Storm with maximum sustained winds of 60kts and a central pressure of 990mb. It's located at 38.5N 56.3W and zipping off to the northeast at 18kts. The remnants of TD10 have continued to drift WNW and although struggling to overcome shear, appears to be making a comeback, and could be re-upgraded to TD10 in the near future. It's presently at about 18N 56W... a few hundred miles east of the Leeward Islands. As of today at 21Z, the season's NTC stands at 81%. Of historical note, today is the 36th anniversary of Hurricane Camille's deadly and devastating landfall on the MS coast.Please visit my tropical Atlantic headquarters.
Posted by at 4:44 PM
15 August 2005
On Sunday night, Irene was upgraded to a hurricane, the third of the season. Since then, the satellite presentation has been quite nice, and it's not outlandish to think that it could become a CAT2 storm before transitioning to extratropical over the central north Atlantic. At 21Z, Hurricane Irene was located at 36.7N 66.0W and tracking ENE at 10kts. The latest satellite imagery suggests that the motion is perhaps even E at 10kts. Estimated intensity is 80kts and 980mb. TD10 formed in the deep tropics over the weekend, but was in a high- shear environment. Only four advisories were written before NHC decided to downgrade it to a low-level circulation. HOWEVER, within about 12 hours, it will be crossing a low-shear zone, and if it takes advantage of that, it could regenerate and become interesting again. I've descibed the NTC Activity index before, and as of now, the season stands at about 79%, which is quite phenomenal for the second week of August! Typically, the bulk of the season is still coming in the next two months!Please visit my tropical Atlantic headquarters.
Posted by at 6:27 PM
12 August 2005
Over the past 24 hours, Irene has become increasingly better organized, and is now just shy of becoming the 3rd hurricane of the season. Intensity as measured by an aircraft was 60kts and 997mb. It is located at 28.7N 67.5W and heading NW at 9kts. This motion is expected to slow down, then make a turn to the north then northeast, but weak steeering flow could make this is a long process, and Irene could thus be a hurricane for quite a while. Currently, there is persistent deep convection over the center, the outer rainbands are weakening, and the outflow aloft is improving, helping this young tropical cyclone to breathe better. The shear and SST environment are favorable for further development, and I don't see any reason why this will not become Hurricane irene later tonight. Elsewhere, there's a potent tropical wave in the deep tropics at about 12N 43W. It exited the African coast on the morning of August 8 and has now had 4 days to organize a broad circulation. This could become TD10 or TS Jose over the weekend.Please visit my tropical Atlantic headquarters.
Posted by at 6:24 PM
11 August 2005
It has been a week since my last update, and since then Harvey came and went, finally making the transition to an extratropical cyclone over the north Atlantic, never having made it to a hurricane. And TD9 that I mentioned in that update had briefly become TS Irene for a day, then weakened back to a TD, but over the past couple of days is making a genuine effort at looking impressive. Now back to a TS and forecast to become a hurricane, Irene is between Puerto Rico and Bermuda and heading northwest. It had been battling dry Saharan air that sometimes lingers over the ocean, as well as vertical wind shear. As of 21Z today, TS Irene was located at 25.7N 63.9W and tracking WNW at 13kts. The maximum sustained winds are 45kts and the central pressure is 1000mb. Conditions continue to improve and it is expected to reach hurricane intensity by Friday night. The forecast track is most interesting... it could nip the US coast near Cape Hatteras or recurve before hitting. At any rate, the closest approach should occur sometime on Tuesday.Please visit my tropical Atlantic headquarters.
Posted by at 6:13 PM
04 August 2005
Since my last update on Tuesday, TD8 has gotten much better organized, has become completely tropical in nature, and was upgraded to TS Harvey on Wednesday morning. It passed just south of Bermuda as a moderately strong tropical storm, and is now not far from being a minimal hurricane. As of 21Z today, satellite-based intensity estimates are 55kts and 994mb. It's east of Bermuda and heading ENE into the open ocean. Over the past week, I've been watching a large easterly wave trek across Africa and out into the eastern Atlantic. It entered the Atlantic on Monday morning and has been drifting westward since then, gradually getting better organized (http://einstein.atmos.colostate.edu/~mcnoldy/tropics/hovmoller/atlantic/). Today at 21Z it was upgraded to TD9 and has everything in its favor to quickly become Irene, the 9th named storm of the season, by tomorrow. It's located at 12.7N 34.5W and tracking W at 10kts. Intensity is 25kts and 1009mb and is forecast to become a hurricane during the weekend.Please visit my tropical Atlantic headquarters.
Posted by at 6:07 PM
02 August 2005
Sorry for the lack of updates the past week, I was on vacation. During that week, Franklin meandered off the east coast of the US and then zipped off into the north central Atlantic, racking up 8 "named storm days", and Gert formed and followed a nearly identical track and intensity as Bret, collecting just 1 named storm day, neither making it to hurricane intensity. Today at 21Z, a somewhat subtropical-looking disturbance was upgraded to TD #8, and is headed generally toward Bermuda. The deep convection is quite removed from the low-level center, and there's an upper Low to the southwest of the surface Low. All-in-all, it doesn't look very tropical to me! It's located at 28.5N 68.7W and moving N at 11kts. Satellite- estimated intensity is 30kts and 1009mb. It is forecast to gradually intensity to a weak tropical storm, at which point it would be named Harvey. A Tropical Storm Warning is in effect for Bermuda, and it should pass very near the island tomorrow night. Elsewhere, there's a healthy easterly wave at about 11N 24W, tracking slowly westward at 5kts. Although not real impressive now, conditions are favorable for it to develop. This wave's origins can be tracked back to far eastern Africa on July 26... so it took about 8 days to get to its current location near the Cape Verde Islands. The NTC for 2005 stands at 68.4% as of this afternoon. The average NTC for this time of year is somewhere around 8%.
Please visit my tropical Atlantic headquarters.
Posted by at 6:28 PM