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The series of tropical cyclone updates continue.  I'm looking forward to ending this.  No, not because I'm lazy. :-)  But because this is ridiculous.  The U.S. has already had two tropical storm landfalls (Edouard and Fay) and two hurricane landfalls (remember Dolly).  And Cristobal nearly made landfall in North Carolina... just missing an actual "landfall", scraping along the coast.  Not only is that pretty unbelievable... four landfalls - two hurricanes - before we even hit the season's climatological peak (September 10th), but look at that list...  The landfalls are Dolly, Edouard, Fay and Gustav... consecutive storms.  (Cristobal would've been consecutive as well.)  Now Hanna and Ike pose a serious landfall threat?!?!?  Unreal.  In the update, "below the fold", I was going to take a historical look at this, but this level of activity is surprisingly not uncommon.  So, let's just get to it...

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Quickly, in reference to the historical precedent, even if Hanna and Ike both make landfall in the U.S. as hurricanes, this level of activity is not historically unprecedented.  How many other seasons have had four+ U.S. hurricane landfalls?  1869 (4), 1880 (4), 1886 (7), 1888 (4), 1893 (5), 1915 (4), 1916 (5), 1933 (5), 1964 (4), 1985 (6), 2004 (4), and 2005 (6).  So... since 1850 there have been 12 seasons with four or more U.S. hurricane landfalls.  We've "only" seen two so far.  So, even if Ike and Hanna hit as hurricanes (becoming less likely as Hanna struggles), this isn't at all unprecedented... unfortunate, yes... unprecedented, no.  Of course, we'd only be about half way through the hurricane season, climatologically speaking, after Hanna and Ike.  So it would seem like there's a real chance of five or six such landfalls (though, who knows... we can go through cycles of activity and inactivity even within a season).  But even five or six isn't unheard of - though it is much less common.  If you want to check out the historical storm tracks, I recommend the simple track map site at Unisys.  Now, on to Hanna and Ike... first Hanna...

Good news on Hanna... Tropical Storm Hanna took an absolute beating from wind shear last night.  The shear has relaxed a bit this morning, but conditions are still not very favorable.  In fact, this is what she's looking like this morning:

...if that just looks like some indistinguishable, amorphous blob to you, you're right.  Hanna has lost almost all semblance of organization.  There is still a low level center... that's what "drives" these storms; so, she can still recover if atmospheric conditions improve for her.  But she's really been knocked back significantly.  The latest aircraft reconnaissance fix has Hanna's pressure up to 996mb.  It was 10mb deeper (lower; lower = stronger) last night.  That same recon also only go maximum flight level winds of 50kts (55-60mph) at flight level.  That equates to only 40-45kts (45-50mph) surface winds.  The National Hurricane Center's latest advisory still has Hanna as a 60mph storm, but this is clearly "generous".

More good news from Hanna is that the track models have shifted east:

..obviously, this isn't good for those in harm's way.  And note that there's still considerable spread in the models.  But it's good news because, as we discussed yesterday, landfall in a location infrequently struck - such as Jacksonville or Savannah - can cause much more problem with respect to tree damage and its collateral effects (power outages, etc). So, a landfall closer to Charleston - while not good for those folks - is "better" in the overall picture.  Now, you know I've been favoring a further south landfall.  So, the question is - is this model shift correct?  I'd say "yes".  Due to some small changes in the timing of the approaching cold front which will pick Hanna up (it is moving faster), Hanna will be forced to turn more northward faster.  As a result, I believe Hanna will come ashore north of my previous expectations... nearer to Charleston.

And what will her intensity be when she hits?  Well, one has to wonder if she'll completely dissipate in the near term, given how weak she is.  Frankly, that's a very real possibility, but I'm assuming it won't occur, since every model indicates she'll survive, and her low level center - the driver of the storm - has been very tenacious.  This image:

...shows the model intensity predictions.  The "best" of the models (GFDL and HWRF... though the HWRF has struggled this season - to put it nicely) both show Hanna landfalling as a 70-80kt (80-90mph) Category 1 hurricane.  However, there is some brand new HWRF and GFDL data not yet available on those graphics.  The HWRF now shows basically no intensification, and landfall as only a moderate tropical storm.  The GFDL concurs, but it slightly stronger.  These models are showing no response from Hanna when she passes the Gulf Stream.  So, I suspect she'll get a bit stronger - again, assuming she even survives the near term.  So, I'm anticipating landfall as a Category 1, 65kt hurricane.

Bottom line... all good news from Hanna... weaker and likely to strike a less vulnerable location.  But she does still need to be monitored closely.  Hanna has a history of extremely deep convection (strong thunderstorms) which basically acts like a pump to drive the storm's central pressure down.  So, she does have an opportunity for more significant intensification, if atmospheric conditions become less hostile for her.  But, at this point, she looks like she'll be a marginal hurricane coming ashore in South Carolina.

As for Ike, I'll be a little more brief on him, since he's further down the line.  However, Ike could be a more serious concern, especially given Hanna's recent weakening.  Ike is already a pretty impressive storm.  Check out a satellite loop of Ike.  No eye.  No CDO (central, dense overcast... that's when there's a solid area of deep convection centered over the storm center).  But a very impressive circulation:

...and atmospheric conditions will continue to be favorable for Ike.  There has been some talke of northeasterly wind shear developing over Ike, be he'll be move west or even temporarily westsouthwest at that time.  In other words, he'll be moving with those upper level winds.  They could still yield some shear if the wind velocities are strong enough.  But, personally, I'm skeptical that there'll be significant shear.  And the "best" models (GFDL and HWRF) agree and do not weaken Ike in the face of this supposed shear:

On that plot, don't get too scared by the HWRF, as it's been too strong with almost every storm all year.  But even the GFDL shows no weakening frmo the shear and intensifies Ike to a Category 3 (the weakening late in the GFDL is due to landfall in Hispaniola).  Again, as with Hanna, there is some new HWRF and GFDL data for Ike.  The HWRF remains ridiculously strong, with a strong Category 4 from 78 hours onward.  The GFDL remains more conservative, but still has Ike on the brink of a Category 3 late in the period.  My opinion is that she shear will not weaken Ike.  But it may halt intensification for a while.  So, he'll probably slowly get up to a minimal hurricane by tomorrow, then hold there throughout the day Friday, then resume intensification on Saturday.  I suspect he'll be a major hurricane by early next week.

Where he goes is anyone's guess.  The models are all over the place, but there has been a general, not insignificant north and east shift:

...note that the new GFDL is north of the track in the above plot (the new HWRF is similar).  Through five days, there's good agreement... into the southern Bahamas (except for the EGRR - which is the UKMET).  Beyond that is the problem.  The newest American model run has such a sharp turn that Ike turns out to sea without impacting the U.S.  The European model takes Ike to the Florida coast then makes a hard hook up the coast, just offshore, until landfall in North Carolina.  The Navy model clips south Florida then hooks up the west coast of Florida.  The Canadian model sends Ike way south, to south of Cuba, before a severe turn through the Yucatan Channel and up into the northwestern part of the Florida Peninsula.  The one bit of agreement here seems pretty clear... Ike will make a turn to the north between 75 and 85 west longitude.  So, bottom line... the key threat is to Florida and the East Coast.  Landfall timing (assuming he does not hook at 75W then go out to sea - as in the American model) will depend largely on where landfall occurs.  And it is way, way, way too early to nail that down.  But we're probably roughly looking at mid-week next week.  The further southeast landfall occurs (like if it's in southeast Florida), the earlier it will be - of course, since that's the direction Ike's coming from.

Gotta end it there.  Wish I could include some more pretty graphics.  But work calls.  As always, I'll try to answer any and all questions and do updates, as time permits.  And I hope I didn't make too many typos... no time to proofread.

UPDATE  2:15PM EDT  First, let me address something a commenter pointed out... There is some concern over one person asserting their opinion in matters of life and property.  That is a legitimate concern.  I do, however, try to present the full range of possibilities, so residents of all potential "target areas" know to monitor the situation.  Also, please check the National Hurricane Center and remember that their's is the official word.  I'm just one voice in the wilderness trying to help illuminate a subject and offer my professional opinion on the matter.

With that, some new info on Hanna and Ike (Josephine is also out there, but not an imminent threat).  New reconnaissance data indicates that Hanna is a little north of where she is supposed to be.  The difference is small enough so that it's difficult to tell whether she has moved or reformed northward.  Here's how Hanna looks now:

...the center, as located by recon, is near the southern edge of the brighter white clouds (convection).  In that image, you can also see that Hanna has regained some structure.  Nonetheless, it is not impressive and Hanna has not strengthened.  That same recon report indicated a central pressure of 996mb... little changed from this morning, and indicative of a weak system.  The 11AM EDT NHC forecast still indicates some intensification, and I'm inclined to agree, given the improved structure.  But I'd go just a bit weaker than they show... putting Hanna right at 65kts (75mph) at landfall.  But that's splitting hairs; a 5kt difference won't mean much.

The big deal is the track.  My thinking already shifted north earlier today due to the speed of the front.  Now, with Hanna nudging more northward, it looks like she'll even run north of what I was thinking earlier.  Here's where the NHC has landfall:

...notice they also have landfall a little later (Sat AM rather than Fri PM).  Given the trends, I suspect even the NHC isn't far enough north now.  Like I said in the "intro" for this update... the NHC is the official word; pay attention to them... but based on these trends and shifts, I'm now thinking that Hanna may strike closer to Cape Fear or Wilmington, NC.  And given that it'll take a little longer to get further up the coast, early Saturday morning looks like a good bet on the timing.

Quite a change from yesterday, as Hanna has been much more difficult to forecast than Gustav.  I should also note that all of the latest model guidance also continues to shift eastward.  Most of it is new, so not available on one of those pretty plots from Allan Huffman's page yet.  So, I've got no pretty graphics for you, but the models are now focusing on landfall between Myrtle Beach, SC and Cape Lookout, NC... then up along the Mid-Atlantic coast into New England.  The good thing is that that keeps most of the land areas on the west (weak) side of the storm.  Only eastern North Carolina and portions of New England will be on the east side... and Hanna should only be a modest tropical storm by the time she reaches New England.

As for Ike, he's pretty much status quo... even from a model guidance perspective.  The new American model continues to show a hard right turn out to sea.  The new Canadian model turns him a bit sooner, but still aims towards Florida.  The UK model continues with its northern outlier solution.  The new HWRF and GFDL still head for the southern Bahamas by Monday, though the GFDL has nudged back south into Hispaniola again.  The only big change is the new Navy model (NOGAPS), turning Ike early enough to miss the U.S. (barely ... FL and NC still catch some fringe effects, and New England may as well - that's beyond that model's range).  The new European model run is not yet in.  So, little change in the guidance from Ike, maybe some overall eastward shift and an increased chance that he'll go harmlessly out to sea... let's hope.

That's about it.  But since I didn't talk about Ike much, here's what he's looking like now:

...again, not much change from earlier.  So, he's pretty much status quo.

And as I finish this up, the new Euro model has just begun becoming available.  It has Hanna landfalling near or just north of Charleston, SC on Saturday morning.  This south of most other guidance, but it is notably north of its previous run.  It has not completed enough of its run to make any intelligent statements about what it does with Ike.... but through Saturday, it's pretty similar to its previous run (it's previous run had Ike clipping Florida then hitting eastern NC, possibly on its way to New England - but that is uncertain conjecture).

That's all for now.

Extended (Optional)

Originally posted to millwx on Wed Sep 03, 2008 at 06:09 AM PDT.

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