The remnants of Hurricane Alex

Monterrey, Mexico, possibly the wealthiest city in that country, is usually too far inland to be affected by hurricanes from either of the two main basins. Hurricane Alex, however, continued to do things most of us weren't prepared for. Monterrey paid a heavy price.

Intense rain from Hurricane Alex shut down Mexico's richest city, Monterrey, on Friday, as floods killed six people, swept away cars and swamped wealthy suburbs with mud and rocks.

More than a year's worth of rain fell in three days from the first named Atlantic storm of the 2010 season, swelling dry river beds and destroying chunks of highway in the city, about 620 miles (1,000 km) north of Mexico City.

More pictures here.

Hurricane Alex crosses the coast...

Alex made landfall across the North East coast of Mexico at Soto La Marina at about 0200 GMT. It has now been downgraded to a Tropical Storm. At the time of landfall the wind speeds had risen to over 90 knots (169 kmh/105 mph) making Alex a category 2 strength hurricane.

Alex will likely dissipate over the next day or so as it encounters the Sierra Madres. That will result in heavy rainfall and possible flooding/mudslides.

A couple of points of interest:

1. There has not been a category 2 hurricane in the Atlantic basin in June since 1966 (Alma).

2. Alex was/is huge. The radius of maximum winds was wide and hurricane force winds extended well over a degree of latitude (60 miles) from storm centre. The webcams at South Padre Island provided some interesting viewing until salt spray and rain obscured them. Some of the weather stations we were monitoring ceased transmitting as the worst winds passed through.

Hurricane Alex .... Updated

Update: 30/1445Z
Hurricane Alex has intensified slightly and is now well defined. Central pressure was measured at 961 millibars with an initial intensity of 70 knot (148 kmh/92 mph) winds at the surface.

This thing is a behemoth. As you can see from the satellite shot taken less than an hour ago, Alex occupies a huge portion of the Gulf of Mexico.



Alex has been upgraded to a Hurricane by the NHC. That makes it the first hurricane of the 2010 Atlantic season and the first June hurricane in that basin for 15 years. (Hurricane Allison)



Alex will probably intensify before it makes landfall sometime Wednesday. The wind shear is below 10 knots, the sea surface temperature is extremely high and there is not enough dry continental air to stifle growth.

The central pressure has dropped rapidly to 973 millibars and surface winds have reached a sustained 65 knots (120 kmh/75 mph). The system has altered more to the west and is now tracking about 280 at 8 knots (15 kmh/9 mph). Intensification estimates vary but the official forecast is that Alex will remain a Category 1 Hurricane until landfall with sustained wind speeds of up to 80 knots (148 kmh/92 mph).

Landfall is a question. The track guidance provided by the models is quite wide so exact landfall predictions are difficult and of low confidence. The other thing is that this cyclone is huge. The radius of maximum winds is about 15 miles from centre, but the Tropical Storm Force winds have a radius of almost 3 degrees of latitude or 180 miles. That means that Alex will cut a wide swath into Mexico and Texas no matter where it makes landfall.The storm surge is now expected to be around 5 feet in the areas of landfall and 2 feet or greater as far away as Louisiana. That will have a negative effect on the oil blowout area by driving the surface slick towards shore. Along with the surge of seawater and the high winds, Alex will probably drop huge amounts of torrential rain as it crosses the coast. Flooding is almost inevitable. These webcams right on the beach at South Padre Island should give us an interesting look.

Alex is expected to make landfall in less than 24 hours.

Alex gives the Gulf oil spill response a whack

Here we go.

Gulf coast residents had feared a tropical storm. Monday's weather wasn't that bad, but it was bad enough to bring relief efforts on the water to a halt. Seven miles out to sea there were rolling seven-foot seas. It makes the skimming operations to recover oil much more difficult. Monday's foul weather also forced BP to delay plans of adding a third capturing system which would help the "Q-4000" and "Discover Enterprise" recover some of the 60,000 barrels of oil that continues to spew into the Gulf daily. For the armada of boats dealing with the spill, tropical storm Alex is serving as a dress rehearsal of sorts for what is expected to be an intense hurricane season here on the gulf.

Alex is now passing north east of the ocean buoy in the Bay of Campeche. Pressure is dropping although the winds seem to be reasonably steady at around 30 knots. The storm itself has developed an eyewall. You can see the spiral rain bands forming. It looked briefly as though Alex was picking up some dry continental air, although the latest photo below indicates that it may be filling in. NHC reported that there was some entrainment* of dry air from the west. That may have the effect of limiting Alex's growth.



The webcams at Padre Island are starting to show the effects of Alex as it approaches.

Alex spinning up, speeding up and heading for Texas

The US National Hurricane Center has now issued Hurricane Warnings on Tropical Storm Alex for the south coast of Texas and northeast coast of Mexico. Alex is gaining strength and will probably develop into a Hurricane by no later than tomorrow and make landfall on Wednesday night.

The wind shear is a little high but its forecast track takes it through decreasing shear in the next few hours. Sea surface temps are very high and the central pressure has dropped to 982 mb. It is moving North Northwest at 10 knots (12 mph/19 kmh).

As it stands now, Alex will have very little direct impact on the oil blowout in the Gulf of Mexico. However, given its track, intensity and radius, it will likely produce strong southerly winds and generate surface currents which will drive the surface oil slick onto the coast.

The big question now is how much damage this storm will cause. The expected storm surge could bring a rush of sea water inland of up to 3 meters above tide as Alex approaches and about a meter above tide over a wider area of the Texas/Mexico coast. There is some concern that the surge will reach the area of the oil slick, although it should be under a meter.

Coupled with all that is the fact that Alex, once it makes landfall is forecast to contain 80 knot (148 kmh/92 mph) winds gusting to 100 knots (185 kmh/115 mph) and will release huge amounts of moisture as it moves inland.


An interesting note. The ocean buoy centered in the Bay of Campeche is showing rapid and significant drop in atmospheric pressure and a rapid rise in wind. That particular buoy is almost directly in Alex's path. I'll be watching that buoy and I'll be checking out the webcams on South Padre Island.

Alex back in warm water... and growing.

Alex emerged from the Yucatan intact and with enough organization to quickly regenerate. While it had been downgraded to a Tropical Depression over the Yucatan, it is now back to Tropical Storm and the expectation from both guidance models and forecasters is that Alex will spin up to a Hurricane sometime before it makes its next landfall.

The question still remains, where will Alex make landfall and how much effect will it have on the oil blowout off Louisiana. (And should the containment effort be interrupted because of a possible hurricane?)

Based on models and forecasts, the probability of Alex plowing through the oil spill is very low. That doesn't mean there won't be some effects felt in that area. Significant winds, seas and swells will have the effect of blowing the surface oil towards the coast.

The area of low wind shear, high sea surface temperatures (29.5 C) and high mid-level moisture all suggest Alex has the necessary conditions to fuel it further. Models present a wide range of possible landfalls from north of Corpus Christi, Texas to Tampico, Mexico. For the next 48 hours Alex is expected to continue a slow North West movement as it intensifies.

I'm keeping an eye on the ocean buoy (42055) in the Bay of Campeche over the next day or so.














I'm also watching the weakening ridge over the central US. If two of the models are correct, further weakening will have the effect of steering Alex poleward.

Alex. Landfall in Belize.

Tropical Storm Alex made landfall at just after 2300 GMT yesterday. The movement slowed slightly and, as expected the storm lost intensity. It has been downgraded to a Tropical Depression for the time being. It dropped large quantities of moisture on Belize and the surrounding environs.

A good description of the passing of Alex through coastal Belize is provided by the Cay Caulker website where the writer describes the rapidly changing weather.



Alex will soon leave the Yucatan behind and enter the Gulf of Mexico. What happens after that is currently a guess. The high sea surface temperatures and low wind shear will give Alex renewed energy and reintensification to Tropical Storm status and possibly into a hurricane. Everything now depends on how much the storm slows once over water and how long it stays there.

Right now there is a ridge of high pressure north of Alex which would have the effect of causing the storm to alter to the west and make an eventual landfall on Mexico's east coast. A good number of computer models are providing that forecast guidance, however, there are some models and model ensembles which have the ridge weakening enough to cause Alex to recurve poleward and toward the northern reaches of the Gulf of Mexico.

At this point a high confidence forecast is going to require a later-in-the-day model run with more atmospheric data. That underscores another point of contention.

On at least two U.S. television stations the personalities reading and pointing at the weather conditions made statements to the effect that Alex had made landfall well to the south of the Gulf of Mexico and that all danger of the storm becoming involved with the oil blowout in the Gulf had now passed. Nothing could be further from the truth.

A majority of tropical storms which make landfall on the Yucatan survive and continue to present a threat with a large percentage of them strengthening to hurricanes. As the US National Hurricane Center states in its forecast discussion:

ALL OF THE MODEL UNCERTAINTY WITH THE TRACK OF ALEX OFFERS A
REMINDER TO NOT TO FOCUS ON THE EXACT FORECAST TRACK...PARTICULARLY
IN THE EXTENDED PART OF THE FORECAST PERIOD...WHERE AVERAGE
FORECAST ERRORS CAN BE 200 TO 300 MILES.

I suspect the forecaster at NHC added that statement to the discussion because of the unsubstantiated conclusions being reached by US media broadcast personalities.

Alex remains a danger and at present we have no conclusive idea as to where it will end up.

Tropical Storm Alex

The tropical wave we have been watching in the Caribbean has evolved and gained enough energy to become the first named storm of the 2010 Atlantic hurricane season - Tropical Storm Alex.


The direction this cyclone will take is still only a best guess at this time. There is considerable variance in the forecast guidance models although for the next 24 to 48 hours the estimate is that Alex will move in a general direction of West Northwest at about 9 knots (16.6 kmh/10.4 mph).

The wind shear over Alex remains low and the sea surface temperatures are very high. There is plenty of moisture and the storm is producing heavy rainfall which does not bode well for the estimated landfall areas of Honduras, Belize and the Yucatan peninsula.

What happens after Alex crosses the Yucatan is a big question. This storm is intensifying quickly and stands a good chance of emerging from the Yucatan landmass with enough energy to become a hurricane within the next 96 hours. Most forecasts are taking guidance which suggests that once Alex is in the Gulf of Mexico it will be influenced further westward making landfall somewhere around Tampico, Mexico.