Overall, the last 18 hours, since yesterday's entry in this diary series, the news has not been good with these tropical systems. Hanna has recovered some. She has lost all convection this morning, so any further intensification should be slow - if at all. But she is, nonetheless, back up to a formidable storm, just shy of hurricane strength. Meanwhile, Ike has absolutely exploded... unbelievably becoming a Category 4 hurricane. This may not last, but he should remain a strong storm. The one bit of good news since yesterday is that there seems to be increasing model guidance suggesting that Ike may not quite ever reach the U.S. But that's a long way off, there is not model agreement on that (just a little more hint of that on some models), and even some of the models showing a "miss" are too close for comfort. Details below the fold...
First a quick caveat: A commenter yesterday brought up an important issue... please keep in mind that when I give a forecast here, it's just my lone voice. You should always refer to the National Hurricane Center for the official advisories. There are other "voices" out there worth hearing, as well, like Dr. Jeff Masters over at Weather Underground. (Of course, there are some not worth hearing as well... like Joe Bastardi of AccuWeather... a hype-monger and fear-monger extraordinaire.) Anyway, just want to make sure you all read these write-ups with eyes wide open and ears open to other voices. Now, on to it...
One of the few bits of good news this morning is that Hanna will clearly not be strengthening at any rapid pace over the next 6-12 hours or so. Besides the fact that upper level conditions are marginally favorable - with some considerable wind shear, take a look at how she currently looks on satellite imagery:
...that is an infrared image. The deep convection (strong thunderstorms) are noted by the deep orange/red colors. The center of Hanna is near the center of that image. Notice the lack of deep convection near her center. The convection acts as a "pump", pushing air out of the storm's center and lowering the pressure, intensifying the storm. So, the lack of convection means no intensification. To be clear, the latest aircraft reconnaissance reports show that Hanna is not weakening either. But dramatic intensification is unlikely. In fact, here are the latest intensity models for Hanna:
...the black line is the official National Hurricane Center forecast. Notice that they are higher than all guidance. No guidance shows any strengthening, and many forecast show slight, slow weakening prior to landfall (early Saturday morning). Frankly, either is equally possible in my view. So, I think Hanna will be within 5 or 10 kts or mph of her current intensity by landfall. So, she'll either be a strong tropical storm or a minimal hurricane. And as for where that landfall occurs... well, here's what the guidance shows:
...and here's what the National Hurricane Center has:
The agreement there is pretty solid, with the focus between Myrtle Beach, SC and Wilmington, NC. A few models are furth southwest down the coast, but they are among the worst performing models this year and can probably be discarded. A few more recent models have come in that aren't on that chart, but they show little difference from the tracks shown above. Yesterday, I shifted my thinking up to Wilmington, NC, given the model trends and agreement. That looks like it has shifted to the southwest a bit. I'm not a fan of just jumping around with the models, but NOAA (National Oceanic and Atmospheric Administration) added some extra dropsondes for the latest model runs. So, given the nearly unanimous slight westward shift, I'm buying it.
Bottom line: Landfall near the SC/NC border early Saturday morning as a borderline hurricane. Note that Hanna doesn't look entirely tropical in nature. As a result, she has a large wind field. So, folks pretty far up the coast could see some strong winds. On the bright side, as she'll only landfall as a 60-70kt (70-80mph) storm, those winds far up the coast won't be destructive hurricane force winds. But they could cause some tree limbs and weak trees to come down, yielding some power outages, through eastern NC/VA. There will likely even be some gusty winds further up the coast, all the way into eastern New England, as Hanna swings through there by Sunday. Heavy rains will also cause local flooding, but shouldn't be too severe, as Hanna will be moving along.
Then we turn to Hurricane Ike... this is "him" as of this morning:
Look at that storm. Incredible. It exploded Wednesday evening. Hte convection around the eye is a little less symmetrical now, and there are some hints of shear beginning. So, Ike's intensification cycle is likely over. But he has ramped up, unbelievably, all the way to a Category 4 hurricane already. So, what's he going to do? To be clear, that remains a huge question.
Regarding his track, this is what the models show:
...and I should add that the new model runs not on that map have improved the consensus some. A new American model run (AVNO on that plot) has shifted southwestward. It is still north of the cluster of models, but it is now closer. This is important (and unfortunate) because the American model is the one showing Ike having the easiest time hooking harmlessly out to sea. On the plus side, even its new, further southwest run still curls him out without impact - just a glancing blow to the Bahamas, but nowhere else.
...that said, the overall bulk of model data is a bit more suggestive of an out to sea track, in spite of the new American model run. Here's how the models that go beyond day 5 line up compared to yesterday: The Canadian model yesterday hooked Ike into the Gulf then up into western Florida; today it has no landfall, but brings Ike dangerously close to Florida, North Carolina and Massachusetts. The European model yesterday had a North Carolina and New England strike; now, it does allow for landfall in Florida, but then pulls Ike offshore and just lingers him in the southwest Atlantic. The American model we've already discussed. The Navy model had Ike coming up the west coast of Florida; it now has him scraping Florida then moving up to a landfall in extreme eastern North Carolina, followed by a due north motion up the Mid-Atlantic coast. The UKMET only goes out to day six, so I can't say much on it compared to yesterday... except that it looks similar (with its more north track, like the American model).
So, other than the two models which are outliers to the north, the universal trend has been northeastward. Therefore, the chances of Ike going out to sea seem to have increased. Nonetheless, if we assume the northern outliers are wrong (though there is no guarantee there!), two of the other three models do show a landfall, and the third is a major threat. So, clearly, we need to stay on top of the situation with Ike.
Here's what the National Hurricane Center track is for Ike:
...looks pretty reasonable. They're on the north side of the southern cluster of solutions. They're doing this, it seems, in deference to the UK and American models. That is certainly reasonable. My own thinking is that the track will be a bit further south, as I'm more inclined to just toss those two outliers. They've both been poor this year (well, the American has been okay at closer range), and the better performing models are in that southern cluster. Yes, that would mean a greater threat to the U.S. But there will still remain a chance for Ike to hook out. There is a complex upper pattern evolving over the U.S. So, it is just too soon to even guess where/if Ike will make landfall. I believe he's a serious threat, but I won't commit beyond that.
And when he get near (or landfalls?) the U.S., he's expected to be a major hurricane - although he may undergo significant weakening in the next 24-48 hours in the face of wind shear. Here are the intensity models:
...you'd be correct to notice that none of those models show any real significant weakening. (The black line is the official NHC forecast, which accounts for that shear.) But the statistical models, not in that plot and which perform not much worse than the dynamic ones for intensity, show dramatic weakening, down to a Category 1 hurricane. Those statistical models do re-intensify Ike back to Category 2 approaching the Bahamas. So, it still seems likely, even in that scenario, that Ike will reach Category 3 as he nears the U.S. In other words, depending on which forecast you believe, Ike may be going through some significant intensity swings over the next few days, but all models and the NHC forecast show him as a significant hurricane near the Bahamas in five days (Tuesday).
Bottom line for Ike: Just way too soon to say anything definitive. But it seems likely that he will at least be a "threat". And it also seems likely that he'll be a Category 3 hurricane - or at least a Cat 2 - when he becomes a threat. So, we will need to monitor him extremely closely. And I suspect the forecast for Ike will come into better focus tomorrow... especially tomorrow afternoon.
Gotta end it there and get to work. Once again, no time to check for typos, so I hope there aren't many. :-)
UPDATE 11:10AM EDT ...A quick, pretty-picture-free update. Hope to post a more substantive update mid-afternoon. But, for those who haven't seen it, just a relay of the latest official National Hurricane Center forecasts for Hanna and Ike. In case you don't care to read those jargon-loaded discussions, the basic summary of each is... Hanna: A little weaker, still projected to be a minimal hurricane at landfall, and the track is tweaked east a bit, to landfall near the NC/SC border, and a second landfall (as a weaker, possibly non-tropical system?) on Long Island Sunday morning. Ike: Just a bit weaker, further weakening expected (due to the shear discussed above). NHC taking a track in between the various models (so I continue to lean a little south of them... though their track is certainly reasonable).
One point NHC mentions which is relevant and may be helpful in putting a "cap" on Ike... Hanna's long lingering in the Bahamas is churning up the waters. That causes upwelling (water beneath the surface rising to the top). This upwelled water is cooler. Cooler water = weaker storm. So, if Ike comes near enough or over Hanna's previous track, he'll hit some cooler water. That's not expected to have a dramatic impact on him, but it could keep Ike from any major re-intensification one he approaches the Bahamas.
One more note, based on the discussion in the comments below... the threat to Hispaniola and Cuba from Ike is reduced based on the slight north and east model trend discussed above. There remains some modest threat for flooding and mudslide problems in Hispaniola. But a direct impact on these locales is looking less and less likely... not 100% out of the question (that's just too far out to be certain), but unlikely. My exclusion of them in the initial discussion wasn't meant to ignore them. Rather, the most significant threat for a direct strike is the U.S. and Bahamas. And I can't emphasize the word "threat" enough - nothing is certain yet, as there is a potential "escape route" for Ike, offshore out to sea. Hopefully, he'll take it.
Not really much new data otherwise. No new recon data. No new models. Those will come in the later update.
UPDATE 2:55PM EDT Since we've been rec-rolled (get it? that's a joke... some levity for this serious topic), I'm not sure how many folks will see this update, but I know some are checking in. And we have some pretty big development in the latest round of model data w.r.t. Ike.
First, with Hanna there's not much to report. Recon is in the area, but not finding anything of significance. Same pressure as before (989mb). Same flight level winds as before (50-60kts). And the models are unchanged, showing landfall near the SC/NC border early Saturday morning. Here's how Hanna's looking now:
...you can see a good swirl, but no deep convection (which would be bright white on this image). So, still, as mentioned earlier, no immediate, significant intensification is likely.
As for Ike, that's where the big news is. All from a forecast standpoint. Nothing new in his initial state. He still looks the same:
...quite impressive, just a bit asymmetric. But on the forecast...
Model agreement has increased dramatically. The American model (the GFS) has shifted significantly southwest. It continues to hold and keep Ike offshore, even enough for minimal impacts on any land. But it is much closer to the Bahamas and U.S. than its previous run. Meanwhile, the UKMET has also shifted in line with other models, bringing Ike into a position flirting with Florida and stalling just offshore Tuesday/Wednesday. Thereafter, given the pattern, the UK model would then turn Ike north and northeast... how much eastward component is impossible to tell, but that would determine whether or not he threatens North Carolina and/or New England. The Canadian is nearly identical, just a bit further east with Ike when he stalls... sparing Florida the worst impacts, but delivering the Bahamas a worse blow. The Navy model is also similar, but allows Ike to pull north a bit quicker next Wednesday. The Navy model runs out a couple days further, so we can see what it does... it misses landfall in NC, but is close, and appears poised to miss New England, also closely... it is close enough so that its surface wind field shows tropical storm force winds along the Mid-Atlantic coast next Thursday. The HWRF (a hurricane-specific model) is also similar, with Ike near south Florida on Tuesday; it does show enough forward motion so that, on its depiction, a Florida landfall would likely occur before the turn. The only "troublesome" models are the GFDL and the Euro. The GFDL has pushed back to its south track, across Hispaniola and Cuba. That's bad news for everyone as Hispaniola and Cuba get hammered and, then, with the further south track, Ike is likely ("likely" because it's impossible to say with certainty, since it's beyond the model's timeframe) not going to be able to make the hook out to sea (it would likely head to Florida). Then there's the real outlier, the new Euro model. It sends Ike so far south, across Cuba - wreaking havoc there, that he misses the cold front expected to pick him up. As such, he just keeps trucking westward into the Gulf of Mexico, finally catching the next cold front northward into central Louisiana next Friday. However, while the Euro has done pretty well this season, its errors have been fairly consistent... it has a notable west bias. So, I believe it is reasonable to expect this model run to be in error. The rest are in good agreement... even the GFDL, though somewhat of an outlier, at least in the overall large-scale pattern, still has Ike getting picked up by the same cold front as the other models.
...but we should keep the Euro in the back of our minds as an indication of the level of uncertainty this far out. It is likely wrong, but let's keep our minds and options open. So, a Gulf threat must be seen as plausible. Nonetheless, it is still unlikely. And the model agreement otherwise has become quite excellent... and we're looking at a threat to the Bahamas by Sunday, and to Florida by Monday or Tuesday (and, again, I emphasize threat ...we are not necessarily looking at a landfall and, possibly not even significant impact, in Florida ...but it looks like a definite "threat"). Thereafter, still too tough to say whether or not it threatens or strikes NC or New England, but models - other than the Euro - have tightened up to a track close to the coast, but just offshore - plenty of uncertainty for that to change, though!
That's about it. Probably no more updates today. So, check back tomorrow!