Alex, strongest June hurricane in 44 years, is now a tropical storm

By: Dr. Jeff Masters , 2:20 PM GMT on July 01, 2010

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Hurricane Alex, the strongest June hurricane in 44 years, is Tropical Storm Alex, thanks to passage over the rugged terrain of Mexico. Alex made landfall at 9pm CDT last night, 110 miles south of Brownsville, Texas, as a Category 2 hurricane with 105 mph winds. Alex was the strongest June hurricane since Hurricane Alma of 1966, which had 125 mph winds as it skirted the west coast of Florida. Brownsville long-range radar shows that Alex's heavy rains continue to pound the Texas/Mexico border region, and satellite estimates of rainfall (Figure 1) show that some of Alex's spiral bands dumped rains in excess of five inches today, in addition to the 5+ inches that fell yesterday. The Brownsville airport received 6.46" of rain as of 8am CDT today from Alex. Alex is being blamed for at least thirteen deaths in Central America and Mexico due to flooding, though none of these deaths occurred in the region where the storm made landfall. Alex spawned two tornadoes that hit South Texas, and there were at least four other reports of tornado funnel clouds that did not touch ground. Alex may continue to spawn isolated tornadoes today over South Texas and northern Mexico.


Figure 1. Radar-estimated rainfall so far today for Alex.


Figure 2. Snapshot of the Brownsville long-range radar showing Hurricane Alex at landfall at 8pm CDT Wednesday June 30, 2010.


Figure 3. Alex nearing landfall in northeastern Mexico at 12:10 CDT June 30, 2010, as seen by the MODIS instrument on NASA's Terra satellite. Image credit: NASA.

Storm Surge
Alex's maximum storm surge occurred along a 50-mile stretch of the Mexican coast centered about 75 miles south of Brownsville, Texas. The National Hurricane Center Sea, Lake, and Overland Surge from Hurricanes (SLOSH) model predicted that the maximum water depth at the coast reached about 5 - 6 feet above ground level (Figure 3.) A storm surge of 1 - 2 feet was predicted by SLOSH for the Brownsville, Texas region. A storm surge of about 2 feet was observed in South Texas at the South Padre Island Coast Guard Station and Port Isabel.


Figure 4. Hurricane Alex's Maximum Water Depth (storm tide minus the elevation of the land it is passing over) computed using the primary computer model used by the National Hurricane Center (NHC) to forecast storm surge--the Sea, Lake, and Overland Surge from Hurricanes (SLOSH) model. The accuracy of the SLOSH model is advertised as plus or minus 20%. The maximum surge occurred to the right of where Alex's core made landfall, over a sparsely populated marshy area. This "Maximum Water Depth" image shows the water depth at each grid cell of the SLOSH domain. Thus, if you are inland at an elevation of five feet above mean sea level, and the combined storm surge and tide (the "storm tide") is ten feet at your location, the water depth image will show five feet of inundation. For more information on storm surge, consult our detailed storm surge pages.

Alex in historical context
Alex is the first June hurricane since Hurricane Allison of 1995. There have been only eleven hurricanes in May or June since 1945; only four of these were major Category 3 or higher storms.

Alex's bizarre behavior
Alex had several rather remarkable features I've never seen in a hurricane. Firstly, it underwent an eyewall replacement cycle as a Category 1 hurricane with 80 mph winds. Usually, we don't see the inner eyewall collapse and an eyewall replacement cycle occur until a hurricane reaches Category 3 strength. I've seen it happen on occasion to a Category 2 storm, but never a Category 1. Secondly, after Alex's inner 9-mile diameter eyewall collapsed at 10am EDT yesterday morning, an outer spiral band began to become the new eyewall. Winds in this outer spiral band/new eywall increased as the day progressed, as typically happens in an eyewall replacement cycle. However, part way through that process, Alex suddenly reversed course, and was able to build a small inner eyewall with a 12-mile diameter that was completed by landfall. I've never seen a hurricane change its mind in the middle of an eyewall replacement cycle and build an inner eyewall so fast. Finally, Alex had an unusually weak winds, considering how low the pressure was. The pressure was more typical of a hurricane one Saffir-Simpson category stronger than what the surface winds suggested.

Elsewhere in the tropics
The latest run of the NOGAPS model predicts the formation of a tropical depression the Western Caribbean on Tuesday. None of the other models is showing tropical development worthy of concern over the coming seven days.

Wind and ocean current forecast for the BP oil disaster
Alex is continuing to generate very rough conditions over the Deepwater Horizon blowout location, with 5 - 9 foot waves and 3 - 4 foot swells. The wind and seas will gradually subside today, according to the latest marine forecast from NOAA. The resulting currents induced by Alex's strong winds will push oil to many protected bays and estuaries that haven't seen oil yet. The latest trajectory forecasts from NOAA and the State of Louisiana show oil will also move westward along the central Louisiana coast towards the Texas border. Winds will decrease to 5 - 15 knots Friday through Tuesday but remain mostly out of the southeast, keeping the pressure on the regions of coast in Louisiana, Alabama, and Mississippi that are seeing oil hit their shores this week.

Resources for the BP oil disaster
Map of oil spill location from the NOAA Satellite Services Division
My post, What a hurricane would do the Deepwater Horizon oil spill
My post on the Southwest Florida "Forbidden Zone" where surface oil will rarely go
My post on what oil might do to a hurricane
NOAA's interactive mapping tool to overlay wind and ocean current forecasts, oil locations, etc.
Gulf Oil Blog from the UGA Department of Marine Sciences
Oil Spill Academic Task Force
University of South Florida Ocean Circulation Group oil spill forecasts
ROFFS Deepwater Horizon page
Synthetic Aperture Radar (SAR) imagery from the University of Miami

Next post
I'll have an update Friday morning. Dr. Rob Carver plans on summarizing Alex in his blog later today.

Jeff Masters

Hurricane Alex (LRandyB)
Weather inbound to Hurricane Alex.
Hurricane Alex

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1292. Levi32
Quoting StSimonsIslandGAGuy:
OK Levi.

But I still say that proclaiming a low's presence now is really, really reaching. ;)

The Aleutian low would pick its teeth with this thing.


Oh ya definitely lol. It's not like proclaiming a low pressure area means it's performing the first step in development. For now it's just your regular 'ole backyard frontal low.

I've seen highs at 999mb and lows at 1026mb. It's all relative. Pressures are way higher than normal over your area right now so a low can exist with a pressure over 1015mb. We shall see if it's any better defined tomorrow.
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1291. Skyepony (Mod)
I'm thinking we have better than an outside chance of seeing an invest or worse in the NE Gulf pulling together over the next 3-4 days. That ULL is passing through the FL straits..beginning to show 550mb Vort, trying to work it's way down. Then there's the front with all sorts of energy some of which from Alex, draped across north gulf. Give Alex a few days to no longer be a player, let that ULL get rapped up in that energy over the hot waters & it'd be trouble..

As for Alex I was about 15 miles off & 15kts shy, a few days out & never once said..OMG there's a weakness..he might just about face & run NE! LOL.
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Quoting Levi32:


Lol well I'm not a fan of model worship but they picked the best one to believe. You're right that it doesn't show development, but you know, not even the ECMWF can stop me from finding something to watch lol.


Lol. Me either. I've blob watched since 2008. There were a few even last year that were interesting.
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It is not that rare to get a stationary boundary this far south...that trough was not a true cold front. There was no true seperation of air masses and the temperature difference was nonexistant.
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First off stormpetrol yes he is a brilliant kid second yes I think we better watch that wave near 60W and you are right somtimes and sometimes your not infact nobody is always right so don't beat up your self or think that route your are just like everyone else let me tell you I am quite sure that even Dr. Jeff Masters, Dr. W Gray, Dr. Joe B., Jim Cantore, Mike Sidel or Mr John Foster our local weatherman on news27 has got it wrong many times but try not to make the same mistakes a second time.
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Quoting CybrTeddy:


atmoaggie* Lol I have no idea why I said that.
??? Appears I missed something...

Aw, gee, CT, thanks. But, I'd gladly admit that there are quite a few that make more useful contributions.

(I simply haven't the spare time and some of the others listed are just so danged smart!)

Hey, did anyone list Drak? Should be there. And my short-name is moag.
Member Since: August 16, 2007 Posts: 6 Comments: 12461
looks like we found some in too track
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Quoting DaphneCanewatcher:


Mobilebay...take a look at this...

http://blog.al.com/live/2010/07/gulf_oil_spill_mobile_bay.html
That sure is depressing.
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1281. Levi32
Quoting homelesswanderer:


That may be the "tropical wave" the locals were talking about bringing us rain. They worship the ECMWF don't think it shows development. Lol.


Lol well I'm not a fan of model worship but they picked the best one to believe. You're right that it doesn't show development, but you know, not even the ECMWF can stop me from finding something to watch lol.
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1278. KEEPEROFTHEGATE (Mod)
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1271. stormpetrol 12:33 AM GMT on July 02, 2010
Quoting Baltimorebirds:
Everyone is great on the blog.Not just certain people.Everyone commits to something on the blog.Yes they have the most information,and some people came here to learn.But some people on this blog needs to stop posting things like this.I'm not offended but remeber it's your opinion.

WEll I guess I'm one of those people who needs to stop posting things like this, perhaps you should read my first post with regards to what I wrote , not to discredit anyone, and hell yes its my personal opinion so what's the big deal?

Personally case closed!!! no further comment on this!!!
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Quoting Levi32:
The nature of the blocking ridge to the north could push any low that tries to form in the NE gulf westward right along the coast, and the 18z GFS is picking up on that. The 12z CMC ensembles also show a west movement towards Texas in the ensemble mean.

Day 6:



That may be the "tropical wave" the locals were talking about bringing us rain. They worship the ECMWF don't think it shows development. Lol.
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Quoting stormpetrol:

WEll I guess I'm one of those people who needs to stop posting things like this, perhaps you should read my first post with regards to what I wrote , not to discredit anyone, and hell yes its my personal opinion so what's the big deal?
storm please dont swear at herm she is only 13
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1273. Levi32
Quoting StSimonsIslandGAGuy:
That low is so weak if I burped it will be gone.

Looking at Jax CWA obs, the pressure pattern is flat and the winds are random.


Perhaps a low will form. But even if one does, the northerly shear is so strong now that nothing tropical would form for at least 4 days while waiting for the shear to calm down.


That's why I say wait 3-4 days. Alex's outflow is shearing the gulf right now, but in a way that will allow thunderstorms to keep going off over water and keep things active until shear and surface pressures lower, at which point we will have to start watching for the low to deepen and tighten up. We'll have to see how the front looks in a couple days.
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1272. Levi32
If we compare the frontal boundary to the ITCZ (very similar convergence scheme in this situation), and we saw a vort max like that with a spin on satellite imagery and the kind of wind shifts that surface obs show, it would be considered a low within the ITCZ. Lows can form on fronts too.
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i think that area south of cuba is drawin all the florida gulf moist air
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I am sorry, it is the east end of Dauphin Island, not the west end. This persons house in in Desoto Landing. This is the first time he has seen any oil on the beach.
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1266. Levi32
Quoting Baltimorebirds:
Accuweather.com meteorologist say it's very rare to get a front that far south this time of year.


It is rather rare...this was a strong trough coming into the eastern US. With the front getting stuck over the gulf, it will have to be watched for home-grown mischief any time during the next week.
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Quoting RobertM320:



atmomaggie ??? LOL


atmoaggie* Lol I have no idea why I said that.
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1263. Levi32
850mb vort max is obvious:

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1261. Levi32
Quoting StSimonsIslandGAGuy:


I say it's a front. The low will come later, if at all.


A distinguished spin and vorticity max that stands out from the rest of the frontal boundary is something more than just a regular section of the frontal boundary. I believe a low is forming there, but it should not be a concern for 3-4 days yet until pressures lower in the gulf. A 1018mb low isn't going to develop.
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Quoting StSimonsIslandGAGuy:


I say it's a front. The low will come later, if at all.


surface maps confirms a weak low
Member Since: March 10, 2010 Posts: 1 Comments: 7233
Quoting mobilebayal:

I just got a phone call as I was posting that from someone on Dauphin Island. They said the beach at the west end is now covered in oil. It just makes me sick.


Mobilebay...take a look at this...

http://blog.al.com/live/2010/07/gulf_oil_spill_mobile_bay.html
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1254. Levi32
Buoy observations support the presence of a weak surface low over north Florida, moving southward towards the water.

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Quoting mobilebayal:

I just got a phone call as I was posting that from someone on Dauphin Island. They said the beach at the west end is now covered in oil. It just makes me sick.
I live just off Dauphin Island and was there today. It is not covered but there is more than normal.
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Quoting CybrTeddy:
I've never really made a list, but the bloggers I pay attention the most to is Levi, hurricane23, extreme, StormW, Pat, atmomaggie, stormchaser2007 and miamihurricanes09. They are the one's who I can have a discussion with and learn a lot of very valuable information.

In regards to tropical cyclone development in the GOMEX, it could happen. Trough splits are very common for the month of July and can bring sudden homegrown threats. However, I want to emphasis although the models are in good agreement that something will eventually pop up next week.. we want to see consistency on intensity and track. I want to note that the ECMWF did great with the genesis, track and intensity with Alex. ECMWF caught Alex first, a week in advance right after it was obvious 92L wasn't going to develop. ECMWF develops a Bret like system and a Alex like system. So we'll have to watch that closely.



atmomaggie ??? LOL
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Quoting mobilebayal:

I just got a phone call as I was posting that from someone on Dauphin Island. They said the beach at the west end is now covered in oil. It just makes me sick.
Oh my goodness.That is sad to hear.I myself live in Alabama.I wish this was all a bad dream.My prayers are with everyone on the Gulf Coast.
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Quoting Kristina40:
That's awful mobilebayal. We only got tarballs here in Panama City and that was awful enough. It's going to be a very long Summer for the Gulf Coast.

I just got a phone call as I was posting that from someone on Dauphin Island. They said the beach at the west end is now covered in oil. It just makes me sick.
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Member Since: September 2, 2009 Posts: 130 Comments: 21032
Just want to say I don't want anyone to take the top 5 I named personally , as you all noticed I added and "a few others" and the top 5 I rated wasn't necessarily in the order they were listed either, but hell they are all great it would be difficult to choose.
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That's awful mobilebayal. We only got tarballs here in Panama City and that was awful enough. It's going to be a very long Summer for the Gulf Coast.
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Quoting TexasHurricane:


what is the 1008 milibar?
Actually I'll send you an e-mail, because what I posted is not even half of the article.
Member Since: September 2, 2009 Posts: 130 Comments: 21032

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About JeffMasters

Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.