Kyle comes and goes, Laura forms...

Since my last update on Thursday, the disturbance that was near Hispaniola was upgraded to TS Kyle, then Hurricane Kyle, and  recently transitioned to an extratropical cyclone.  It was around as a named storm for just 3.5 days, and as a hurricane for 1.25 days.  It ended up following the forecast tracks very well, traveling straight north into Nova Scotia as a potent tropical storm.

And as of this morning at 09Z, Sub-Tropical Storm Laura formed in the north central Atlantic and won't be threatening anything but shipping lanes.  It's located near 38N 47W and tracking WNW at 7kts, but that will become N very shortly.  Intensity is 50kts and 995mb.  SSTs are 25-26C, and will be dropping to 20C, then 15C within a couple days.  However, it could still become a minimal hurricane in this time (or "sub-tropical hurricane") if the upper-level temperatures cool off with the SSTs and shear remains low enough, which it should.

Please visit my tropical Atlantic headquarters.

Still two unnamed storms to threaten US east coast...

Very little has changed since yesterday's update, so this will be very brief.  The disturbance north of Hispaniola is still there, and is gradually getting better organized... intensity is now estimated at 1003mb and 30kts.  And the one off the NC/SC coast is also still there, moving very slowly but heading for the coast, now has an intensity of 55kts and 998mb.

Strangely, neither of these systems are numbered or named yet, nor are there even "special tropical disturbance" alerts out for them.  The Florida State University Cyclone Phase Space diagrams are often used to determine the structure of cyclones, whether it be extratropical, subtropical, or tropical, and both of these systems are analyzed as "symmetric warm core" (i.e. tropical) by a majority of models.
http://moe.met.fsu.edu/cyclonephase/ (scroll down to the different models, select a model, then select the cyclone of interest)

If either of these ever get named, the next two names are Kyle and Laura.

Please visit my tropical Atlantic headquarters.

Two systems may threaten US east coast in coming week...

The area of disturbed weather that was over eastern Hispaniola a couple days ago is just now exiting the northern coast of that island, leaving behind yet another round of devastating flash floods.  And as is typically the case, the island devastated the storm as well.  There's barely any deep convection remaining, and no evidence of a low-level center.  However, now that the mid-level circulation is over warm water, and there's minimal vertical shear, its chances for reorganization are pretty high.  In the coming days, it's expected to head north toward New England and Nova Scotia as a strong tropical/extratropical storm.

Elsewhere, a potent sub-tropical Low has formed immediately off the NC coast along a decaying frontal boundary.  Intensity is 1008mb and 55kts, and is located 250 miles SE of Wilmington.  It's forecast to track generally NW toward the coast, strengthen somewhat, and perhaps gradually acquire more tropical characteristics.  You can monitor it from the Morehead City NC radar at http://radar.weather.gov/radar.php?rid=MHX&product=N0Z&overlay=11101111&loop=yes
Regardless of how it's classified, it is and will continue to be a hazard for coastal NC, producing strong winds, high seas, and eventually, a lot of inland rain.

Please visit my tropical Atlantic headquarters.

Hispaniola getting another unwanted dose of heavy rain...

An easterly wave that exited the African coast about 2.5 weeks ago (it's been in no rush) is now hovering over the Puerto Rico and Hispaniola area, and is slowly getting better organized.  Last Thursday, it was centered down near Barbados, and since then has turned northward and is presently over the Dominican Republic and has a 1008mb Low associated with it.  It's nearly a Depression, but lacks a well-defined surface circulation.  The cloud tops have been persistently cold, and the outflow is improving, indicating that the vertical shear is decreasing over it.

You can view a radar loop of the disturbance from Punta Cana, Dominican Republic at http://einstein.atmos.colostate.edu/~mcnoldy/tropics/kyle08/Kyle_22Sep08.gif
(new frames will continually be added, so keep checking it!)

It is forecast to continue moving north over the next few days, and gradually intensify.  The US east coast should be aware of this, as it could be affecting the coast by week's end.  The next name on the list is Kyle.

Please visit my tropical Atlantic headquarters.

Ike finally out of the picture...

For the past two weeks, Ike has been a headline.  But finally, early morning Saturday (local), it made its final landfall as a 95kt hurricane, with a monster storm surge.  And although it was deadly and destructive, in the US as well as other countries, the worst-case scenario was narrowly avoided.  The center of the eye passed directly over downtown Galveston and Galveston Bay, and slightly to the east of downtown Houston.  This placed the largest surge and strongest winds just 10-15 miles east of there.  Amazing to think what those 10-15 miles did to "save" Galveston and Houston... the surge was much less than anticipated, though still substantial.  Despite the destruction that occurred there, anyone would agree they got off very lucky: it could have been MUCH worse.  A mere 10 miles further south, and the death toll would be in the thousands instead of the dozens, and the financial hit would have been the largest in US history.
http://graphics8.nytimes.com/images/2008/09/15/us/0915-nat-IKE-web.gif

Flash flooding and downed power lines are an enormous problem from Texas to Canada in Ike's wake.  Nearly 4 million people are without power, and could be for a long time.  Flooding in the midwest was responsible for several of Ike's fatalities.  The following map shows estimated precipitation in the past week, and you can clearly see the swath from Houston to St Louis to Detroit.
http://water.weather.gov/index.php?layer[]=0&layer[]=1&layer[]=4&timetype=RECENT&loctype=STATE&units=engl&timeframe=last7days&timeYYYY=2008&timeMM=9&timeDD=15&product=observed&loc=conus
(you may need to copy and paste the URL if it's too long)

If anyone has personal accounts from the storm, please feel free to share them, and if you wish, I can share them with the list.

The basin is fairly inactive now, giving Haiti, Cuba, and the US a much-deserved break.

Please visit my tropical Atlantic headquarters.

Ike heading for Galveston and Houston...

The forecast track for Ike has not budged in the last day, and it still looks like Galveston/Houston are in extreme danger.  Ike has strengthened a little to 90kts, but appears that it's finally completing the dragged-out eyewall replacement cycle, which should allow it to intensify before landfall.  It's getting much better organized, with rejuvenated convection encircling the eye.  Its tropical storm force winds already extend inland from Galveston eastward to the LA/MS border.  Hurricane force winds extend out as much as 120 miles from the center now.  This is a VERY large and powerful storm, carrying with it the potential for a 25' storm surge into Galveston Bay.  This surge could be greater than Camille's, Carla's, and Katrina's, so it should certainly be taken seriously.

Galveston Island is already flooding, and Ike is still 200 miles offshore.  Eastern Houston is also expected to flood later tonight and into Saturday morning.  So far, only 1/2 of Galveston had been evacuated... hopefully the remainder make it out in the next few hours, or we could face a catastrophe not unlike the Galveston Hurricane of 1900.  A pier on the Gulf side of Galveston Island is already reporting water levels 6' higher than normal.  And a buoy just offshore from the northern tip of the island is experiencing 19' significant wave heights (individual waves could be twice that high)... and still increasing.

The latest full-resolution visible satellite loop is at:
http://rammb.cira.colostate.edu/ramsdis/online/loop_640.asp?product=tropical_ge_1km_center_relative_vis_floater
and 1-minute imagery from GOES-W is at:
http://rammb.cira.colostate.edu/ramsdis/online/loop_640.asp?product=gew_gwrso_1km_visible_float

A long-range radar loop from Houston is at:
http://einstein.atmos.colostate.edu/~mcnoldy/tropics/ike08/Ike_12-13Sep08_long.gif
and the short-range version is at:
http://einstein.atmos.colostate.edu/~mcnoldy/tropics/ike08/Ike_12-13Sep08_short.gif

You'll find additional reports on the storm at http://topics.blogs.nytimes.com/tag/hurricanes/

Landfall is still expected to occur in the early morning hours on Saturday, but that's when the center of the eye crosses the coast.  Severe weather and flooding is already occurring inland, and will only get worse as the day goes on.  It could come ashore as a CAT3 storm, given its recent trend in appearance.

Elsewhere, an easterly wave that had been strongly sheared is entering a more favorable environment and is now located just east of the Bahamas.  This seems to be related to the remnants of Josephine... it will be monitored for development as it heads toward the southeast US coast.  This could be another potential TS/CAT1 landfall as early as Monday.  The next name on the list is Kyle (unless it's determined that it has enough Josephine ancestry, then it would be brought back as Josephine).

Please visit my tropical Atlantic headquarters.

Ike now a serious threat to the entire Gulf coast...

As of 15Z today, Ike was still an 85kt CAT2 hurricane (945mb), but the feature that is becoming very disconcerting is the SIZE of the storm (defined as the radius of the wind field).  Tropical storm force winds should be affecting nearly all of LA and TX coasts within a couple days.  Right now, hurricane force winds extend out 100 miles to the north and east of the center.  A hurricane warning is already in effect for much of the TX and LA coasts, and Galveston and Houston have begun evacuating.  Landfall is expected just south of Houston in the early morning hours on Saturday as a CAT3 hurricane.  There is a substantial risk for storm surge flooding now through Saturday from Brownsville to Mobile, with the highest risk centered on Galveston Bay.  Ike is already more powerful than Katrina or Rita, as measured by its kinetic energy and potential for storm surge.

Storm surge is influenced by five primary factors: storm size, storm translation speed, storm direction, storm intensity, and bathymetry.  All five are working against the western and northern Gulf coast now, most notably the northern Texas coast, which is at extreme risk.
Ike is a strong storm, and still gradually getting stronger... it's also a large storm, and gradually getting larger.  It is moving slowly, and in a straight line (no curves in the track), and the Gulf coast has an extensive continental shelf offshore.  These all combine to produce an enormous storm surge over a large stretch of coastline.

The Navy has a model that predicts significant wave heights (individual waves could be twice as high as the sig wave ht):
https://www.fnmoc.navy.mil/ww3_cgi/cgi-bin/ww3_all.cgi?color=b&type=prod&area=natl&prod=sig_wav_ht

The NHC produces a graphic showing the probability of a 5' or greater storm surge:
http://www.nhc.noaa.gov/psurgegraphics_at4.shtml

The maximum potential surge height is shown at:
http://icons-pe.wunderground.com/data/images/at200809_surge.gif

And NHC runs a sophisticated storm surge model called SLOSH which accounts for storm motion, bathymetry, topography, etc... a worst-case scenario for a CAT3 Galveston Bay landfall can be found here:
http://einstein.atmos.colostate.edu/~mcnoldy/tmp/ike/galv_cat3_surge.png

Please visit my tropical Atlantic headquarters.

Ike strengthening as it heads for Texas...

Over the past 18 hours, Ike has strengthened by 15kts and 11mb, and much more is likely in the coming days.  As of 15Z, it's at 80kts and 957mb, and it appears that an eyewall replacement cycle is beginning.  This should put a halt on any rapid intensification, but opens the gate for substantial intensification once the cycle is complete.  The motion is WNW at 7kts, and this expected to continue, only gradually speeding up somewhat over the next few days.

You can view a great full-resolution visible image loop at:
http://rammb.cira.colostate.edu/ramsdis/online/loop_640.asp?product=tropical_ge_1km_center_relative_vis_floater

The latest official forecast shows a landfall near Corpus Christi very early Saturday morning as a CAT3-4 hurricane.  In the meantime, SSTs will be in the 29-30C range, and weak to moderate vertical shear.

Some parts of the Texas coast have already begun evacuations, particularly the Galveston and Corpus areas.  So far, Ike is responsible for about 75 deaths in Haiti and Cuba.

Please visit my tropical Atlantic headquarters.

Ike heading into Gulf...

Ike is now just an hour or two away from exiting western Cuba and entering the Gulf of Mexico.  It has just tracked over the same swath that Gustav did as a CAT4 hurricane... a very devastating situation for Cuba.  As of 15Z, Ike's intensity was 70kts and 965mb... tracking WNW at 11kts.

The radar loop from Casablanca, Cuba can be found at http://einstein.atmos.colostate.edu/~mcnoldy/tropics/ike08/Ike_08-09Sep08_csb.gif

The forecast track has continually been shifting westward, and is now centered on Corpus Cristi, TX midday Saturday as a major hurricane.  Under the forecast track, the oceanic heat content is maximized, allowing Ike the most time over the deepest and warmest water.  Vertical shear is also expected to remain very low.  Intensity should start increasing within hours of exiting Cuba, and the storm is already looking impressive on satellite imagery.  It could certainly regain CAT4 status by the central to western Gulf.

Please visit my tropical Atlantic headquarters.

Ike makes landfall on Cuba...

At about midnight local time, Ike make landfall on Cabo Lucrecia as a Category 3 hurricane.  It has since tracked westward across the island, and has recently exited just north of Gulfo de Guacanayabo as a minimal Category 2 hurricane.  Over the coming day, it will pass along the southern length of the island, then cross back over Cuba where Gustav did as a Category 4 storm less than 2 weeks ago.  Then it'll have about 4 days in the Gulf of Mexico prior to a US landfall.

As of 15Z, Ike is an 85kt hurricane, with a central pressure of 960mb.  It's heading W at 12kts.  The storm has lost the majority its deep convection, and the inner core has been disrupted.  It should be able to reorganize quickly over the very high oceanic heat content on the south side of Cuba.  The latest forecast track indicates a Houston landfall this weekend as a major hurricane.  However, 5-day forecasts have an average error of 220 miles, so don't focus too much on the exact forecast track.

Once exiting Cuba, the Gulf will be the factor in how much Ike will reintensify.  Ike will cross over the Loop Current, a deep warm patch of water in the east-central Gulf.  After that, the northern Gulf shelf waters are warm, but not very deep.  In the following two plots, you'll find the sea surface temperature (a "skin" temperature), and the oceanic heat content (an integrated energy content from the surface down to the depth of the 26C isotherm).  As you'll see, the surface can be warm, but if that warmth doesn't run deep, a strong hurricane can stir up cool waters quite easily and weaken.  The exception would be storms that are moving fairly quickly... they may stir up cooler water, but they're already past that patch of cooled ocean by the time it would have an influence.
http://www.aoml.noaa.gov/phod/dataphod1/work/HHP/NEW/2008251gosst.png
http://www.aoml.noaa.gov/phod/dataphod1/work/HHP/NEW/2008251go.jpg

Taking these and other factors into consideration, here is a plot of the MPI, or Maximum Potential Intensity, which I described in Sept 4th's update.
http://wxmaps.org/pix/atlpot.png

Please visit my tropical Atlantic headquarters.

Hanna makes landfall, Ike heading for Cuba, Josephine dissipates...

At about 3am EDT, Hanna made landfall on the SC/NC border as a 60kt (983mb) tropical storm, just under hurricane intensity.
As of 20Z, the center is located near the DelMarVa peninsula and tracking NNE at 21kts.  The radar loop covering landfall can be found at http://einstein.atmos.colostate.edu/~mcnoldy/tropics/hanna08/Hanna_06Sep08.gif

It will now continue N-NE over the east coast, from VA to ME, over the next 24-36 hours, then out to the cold north Atlantic as a potent extratropical cyclone.  Tropical Storm warnings still are in effect from northern NC up through NH.

Attention now shifts to Ike, which as of 15Z, was a 95kt hurricane with a central pressure of 960mb.  It is forecast to intensify as it heads WSW then W, but periodically weaken as well as it passes over Cuba in a couple of days.  Once leaving Cuba, it should head WNW-NW into the central Gulf and up toward the north central Gulf coast.  The northern Gulf coast should be watching this very closely, and be prepared for a significant landfall as early as Friday.

It is located just north of Hispaniola, giving more rain to the already flooded countries of Dominican Republic and Haiti.  Then it will pass over the eastern Bahamas, where Hanna sat for a few days.  You can find the latest infrared satellite image of Ike at http://rammb.cira.colostate.edu/ramsdis/online/latest_image_640.asp?product=tropical_ge_4km_ir4_floater_2

You will find a radar loop from Camaguey, Cuba at http://einstein.atmos.colostate.edu/~mcnoldy/tropics/ike08/Ike_07-08Sep08_cmw.gif

As the time nears, there will also be radar loops available from Casablanca, Cuba, and Key West, FL (Mon-Wed timeframe).  Hurricane Warnings cover the eastern Bahamas, while Hurricane Watches cover the central Bahamas and eastern Cuba.

At 09Z, advisories ceased for Josephine, as vertical shear took its toll on the system.  Regeneration, if at all, would be at least a week away, but very unlikely.

Please visit my tropical Atlantic headquarters.

Hanna nearing landfall...

Just in time for landfall, Hanna is getting organized, and has very strong centralized convection now.  The center is located about 140 miles southeast of Charleston as of 7pm EDT (23Z) and tracking north at 17kts.  At this rate, it should be making landfall somewhere between Myrtle Beach SC and Wilmington NC in about 6 hours (1am local time).

Given the current satellite and radar presentation, it could become a hurricane prior to landfall.

Radar loop from Wilmington:
http://einstein.atmos.colostate.edu/~mcnoldy/tropics/hanna08/Hanna_06Sep08.gif

Infrared satellite loop:
http://www.ssd.noaa.gov/goes/flt/t2/loop-avn.html

Another important consideration is that the storm has a large wind field, so being right under the center doesn't matter so much.  Tropical Storm Warnings and Watches cover the eastern coast from Georgia up to New Hampshire now.... while Hurricane Watches cover SC and NC.
http://www.nhc.noaa.gov/storm_graphics/AT08/refresh/AL0808R+gif/205301R_sm.gif

Please visit my tropical Atlantic headquarters.

Hanna less than a day from US landfall, Ike looming ominously north of Lesser Antilles, Josephine still battling shear...

Hanna is a 55kt tropical storm, finally able to get better organized now that the vertical shear has decreased to less than 20kts.  It is now east of Daytona Beach FL, but heading NW-N toward the Charleston SC area.  Landfall is expected there early Saturday morning as a tropical storm.  Watches and warnings for the coasts can be found at http://www.nhc.noaa.gov/storm_graphics/AT08/refresh/AL0808R+gif/
It's possible that Hanna could become a minimal hurricane just prior to landfall, given the recent trend in organization.
In the coming days, tropical storm force winds, along with the potential for flash flooding and tornadoes, extend up into new Jersey, New York, and even New England, as Hanna transitions to a potent extratropical storm.

Now on to Ike.  Ike is shaping up to be a serious threat to the Bahamas and the US this weekend into the middle of next week.
Vertical shear is presently moderate, but will be decreasing, and SSTs will be 29-30C in the coming week.  As of 15Z, intensity is 105kts and 954mb, and tracking W at 14kts.  It is entering the expected timeframe of strong vertical shear, and it shows!  The storm is quite lopsided now, with nearly all convection and outflow on the south half.  Ike could weaken to a CAT2 storm before the shear lets up in a couple days.  It's then forecast to regain CAT3 or CAT4 status as it passes directly over Hanna-battered Bahamas, then onto extreme southern Florida by late Tuesday.

Josephine is now nothing more than an exposed low-level swirl.  It is still classified as a 40kt tropical storm, but is barely even that.  In the next few days, shear is forecast to remain strong over the system, but in 4-5 days, could decrease a bit and start allowing Josephine to make a comeback.  Again, it is near no land and no islands, even looking out one week.

As a side note, as of today, we are at the amount of activity in an "average" season, and this one's not even half way over yet.  The activity is defined by the Net Tropical Cyclone index, or NTC, which combines the numbers of storms, their intensities, and their longevities, and compares it to a climatological average of each quantity.

Please visit my tropical Atlantic headquarters.

Hanna heading northwest, Ike rapidly intensifies, Josephine getting sheared...

Hanna is succumbing to strong vertical shear and very dry ambient air, and is now not much more than a broad exposed low-level circulation.  It still has some convection associated with it, but it's weak and far removed from the center.  It's still being classified as a 55kt tropical storm, and forecast to reach minimal hurricane status before landfall on Saturday morning near the central NC coast (despite no model guidance supporting that intensity).  It is now located just north of the central Bahamas and tracking NW.

When I wrote my update yesterday, Ike was a 60kt tropical storm with a central pressure of 991mb.  Six hours later, it was at 70kts and 984mb.  Another six hours: 115kts and 948mb.  And yet another six hours: 125kts and 935mb.  So, the pressure fell 36mb in 6 hours, 49mb in 12 hours, and 61mb in 24 hours.  Ike very easily met the criteria for rapid intensification, and also was within 5-10kts of its Maximum Potential Intensity (MPI).  MPI is a theoretical upper bound for a storm's intensity given its location, oceanic and atmospheric environments, etc.  Few storms reach their MPI, and some even exceed it (because MPI is not a flawless quantity).

Here are infrared and microwave satellite images from 0745Z and 1136Z today, with Ike as a 125kt hurricane:
http://www.nrlmry.navy.mil/tcdat/tc08/ATL/09L.IKE/ir/geo/1km/20080904.0745.goes12.x.ir1km.09LIKE.125kts-935mb-224N-550W.100pc.jpg
http://www.nrlmry.navy.mil/tcdat/tc08/ATL/09L.IKE/tmi/85pct/20080904.1136.trmm.x.85pct.09LIKE.125kts-935mb-224N-550W.62pc.jpg

So, Ike reached a peak intensity (so far) at 09Z today, at 125kts and 935mb.  As of the 15Z advisory, it's 120kts and 938mb, still a powerful Category 4 storm.  It is starting to encounter some moderate northerly vertical wind shear, and should continue to gradually weaken over the coming 2-3 days (still a strong hurricane though), then after 3 days, the shear is expected to let up a bit, allowing Ike to reintensify as it heads into the Bahamas early next week.  It's presently located near 23N 58W and moving WNW at 14kts.

Josephine is in a hostile environment and barely holding steady as a 45kt tropical storm.  Like Hanna, its satellite presentation is poor, at best.  It will be in strong shear for the next 4 or so days, then perhaps have a shot at regeneration.  In the meantime, it will track WNW over open ocean... not a threat to any land or island for at least a week.

Please visit my tropical Atlantic headquarters.

Hanna still stalled, Ike nearly a hurricane, Josephine getting organized...

Hanna is still over the eastern Bahamas, dumping rain over those islands, as well as Haiti and the Dominican Republic, both south of the storm's center.  Hanna is responsible for at least 23 deaths already, all due to flooding.  At the time of this writing, the center of poorly-organized TS Hanna is located just east of Great Inagua, Bahamas, and heading north at 5kts.  Intensity is 50kts and 997mb, and forecast to gradually strengthen to a minimal CAT1 hurricane over the next three days.  US landfall is expected early on Saturday near Myrtle Beach... or more correctly, somewhere in the GA/SC/NC vicinity.

Ike is now a 60kt tropical storm (just shy of hurricane intensity) near 21N 52W... several days away from anything.  While that sounds like a good thing, it gives the storm 4-5 days to intensify.  The official forecast brings Ike to a CAT3 hurricane over the Bahamas in five days.  The current satellite presentation is impressive... with symmetric outflow aloft, intense convection gathered over the center, and an eye opening in VIS and IR imagery.  Florida may want to keep a real close eye on this one for next Tuesday-Wednesday...

Finally, Josephine is still a TS as well, and now located near 14N 29W.  Intensity is 55kts, but vertical shear is beginning to increase, and it has a day or so to intensify until the shear becomes oppresive.  It is very far from any land, even looking out a full week.

I posted a brief summary of the "why?" behind the current flurry of activity at http://topics.blogs.nytimes.com/tag/hurricanes/ (Sep2, 7:45pm entry).

Please visit my tropical Atlantic headquarters.

Gustav, Hanna, Ike, and Josephine: the Atlantic is alive...

Since making landfall on LA yesterday morning, Gustav has drifted inland and is now centered near Shreveport LA, dumping copious amounts of rain over LA, eastern TX, AR, and MS.  It is now a 30kt tropical depression, and will continue to spin down.  Gustav was a very powerful and deadly hurricane, certainly not to be forgotten.  It caused tens of billions of dollars in damage and perhaps a hundred deaths across Haiti, Cuba, Jamaica, and the US.

Leaving no time to recollect a sense of normalcy, Hanna is over the Bahamas, Ike is in the central Atlantic, and Jospehine is near the Cape Verdes.

At the 15Z advisory today, Hanna was still stalled over the eastern Bahamas, and was downgraded to a 60kt (987mb) Tropical Storm.  Vertical shear is taking a toll on the system, and it could be a couple days yet until it relaxes.  Hanna is forecast to regain hurricane intensity on Thursday as it heads NW toward the southeast US coast.  Landfall is expected on Friday, perhaps clipping the Daytona Beach area, then up to the Charleston area.  Again, remember even 3 day forecasts can be off an average of 140 miles.  A hurricane warning is in effect for the eastern Bahamas, as far west as Cat Island and Great Exuma, and all the way east to the Turk Islands.

Since my second update on Labor Day, TD9 was upgraded to TS Ike, and is now a 50kt Tropical Storm with a central pressure of 1002mb.  Ike is located near 19N 45W and moving W at 16kts, and is poised to become the next hurricane in a couple of days (and perhaps a major hurricane after that).  In 5 days, NHC places Ike almost exactly where Hanna is now... down to the mile almost (always keep in mind the expanding envelope of forecast track errors with time though)!  So the Bahamas and Cuba should be preparing for this, and after that, the US in a week or so.

Also since my updates yesterday, the potent easterly wave I mentioned that had just exited Africa was upgraded to TD10, then quickly to TS Josephine, the 10th named storm of the season.  It's now near 13N 25W and tracking W at 13kts.  Intensity is estimated at 35kts, and 1005mb (and probably increasing rapidly).  This could become a hurricane within a day, but is at least a week away from any land or island.  The satellite presentation is very impressive now, with what appears to be an eye already forming.


Please visit my tropical Atlantic headquarters.

Hanna now a hurricane...

Minutes after sending my update out today, Hanna was upgraded to a hurricane, the 4th of the season.  Intensity is now 65kts and 985mb, and it's more or less stalled over the eastern Bahamas.

Please visit my tropical Atlantic headquarters.

Gustav makes landfall, Hanna and TD9 heading for US coast?...

Another powerful Labor Day hurricane for the record books.  A little sooner than expected, Hurricane Gustav made landfall near Cocodrie LA at about 15Z today, at an intensity of 95kts and 955mb.  You can watch the landfall via the New Orleans radar at http://einstein.atmos.colostate.edu/~mcnoldy/tropics/gustav08/Gustav_01Sep08_LIX.gif

A buoy located roughly 60 miles south of Pascagoula MS reported 34' significant wave heights** (individual waves could have been much higher).  The water there is about 900 feet deep, and the SST was 30.7C yesterday before the storm got there, now it's 27.9C.
http://www.ndbc.noaa.gov/show_plot.php?station=42040&meas=sght&uom=E&time_diff=5&time_label=CDT
Other notable automated observations come from Grand Isle:
http://tidesonline.nos.noaa.gov/plotcomp.shtml?station_info=8761724+Grand+Isle%2C+LA
and New Canal:
http://tidesonline.nos.noaa.gov/plotcomp.shtml?station_info=8761927+New+Canal%2C+LA

It's too early to know the extent of the damage in southern LA, as the storm is still there.  Levees in New Orleans have already been overtopped, but as of this writing, are still intact.  The next day or so will be the real test as time and pressure wear on... fortunately, the majority of the city is evacuated.  It will now continue to track inland over LA and eastern TX, likely spawning tornadoes and causing major flooding.  Four tornadoes have been reported so far in MS and FL, and flood warnings cover much of LA, MS, FL panhandle, eastern TX, and southern AR.  Without a doubt though, the name Gustav will be retired after this season, with probably ~100 deaths attributed to the storm, and tens of billions of dollars in damage across 4 countries.

TS Hanna is presently crawling (4kts) over the eastern Bahamas, creating flooding problems there.  Latest intensity is 50kts and 994mb.  It will pick up forward speed in a couple days, and then likely intensify to a hurricane as it heads for the southeast US coast on Friday.  Right now, the official forecast places landfall at the GA/SC border, but keep in mind that track errors 4 days out can be significant.  Recent satellite imagery is impressive: a centralized shield of very clod cloud tops (as cold as -85C), perhaps indicating that the jump to hurricane status is nearing.

At 15Z, the disturbance that was near 16N 35W yesterday was upgraded to TD9, and is now at about 18N 40W and tracking W at 14kts.  Intensity is 30kts and 1005mb, and gradual intensification is expected as it heads west.  This could certainly be TS Ike by this evening, and a hurricane by mid-late-week.  In the long term, this could be of great interest to Florida.

And as if the list wasn't long enough already, there's a new very potent easterly wave that has just exited Africa.  It's located at about 12N 20W, and has a 1007mb Low embedded within the wave.  Assuming TD9 takes the name Ike, the next name on the list is Josephine.

Please visit my tropical Atlantic headquarters.

**Significant wave height is calculated as the average of the highest one-third of all of the wave heights during the 20-minute sampling period.