It's been a long while and I've mostly been in lurk mode of late. I visit the site multiple times per day, but only infrequently comment on diaries of particular interest. I'm not a big meta-person, and there's been a lot of that around here of late. And I'm torn between the "Obama's a disappointment" and "he's doing well under the circumstances" crowd... so I mainly stay out of the fray.
But, with a hurricane to POSSIBLY near the East Coast later this week, I'm back to try to keep my favorite online community abreast of the storm. First, my standard intro statement...
I understand that some on here dislike these diaries, esp. when they make it to the rec list, because they are totally off-topic to this site's primary objective and subject. I understand that objection. However, I'm just trying to provide a friendly and, hopefully, informative diary to my fellow Kossacks. So, if some folks see fit to rec it, so be it. If not, it will just roll of the recent diary list along with many others.
Anyway, now across the fold for an update on Hurricane Earl...
First off, I should point out the I focus on the mainland U.S. since my time is limited and most of the DKos readers are located there. I mean no slight to others elsewhere; it is just a matter of focusing my energies. That said, though, I should point out that Earl is posing a significant threat to the extreme northeastern Caribbean even as we speak. Here's the latest satellite imagery from Earl:
...that image is courtesy of NOAA's SSD.
In this image you don't see a major hurricane... no apparent eye and only modest spiral bands. However, don't be misled, Earl looked considerably worse earlier this morning. He (sorry for the male pronoun, I know it bugs some of you... habit... and since it doesn't bother me, not a habit I'll probably break any time soon) has gotten much better organized in the past several hours and appears to be in the process of intensifying. A reconnaisance aircraft from the Air Force is investigating Earl as I write this. At this very moment (11:55AM EDT is when I'm writing this) a new report indicates a surface pressure of about 981mb... this is down 4mb from a couple hours ago. In case you don't understand the meteorology of that, it's quite simple: Storms are areas of low pressure; the lower the pressure the stronger the storm. Often you hear about pressure in terms of "inches", but in the science it is almost always referred to in units of millibars (abbreviated mb). The pressure dropping a couple of millibars in Earl over a couple of hours is NOT a major drop. So, there is not any rapid intensification ongoing. However, Earl is likely intensifying slowly, as the satellite images indicate. Presently, he is officially a minimal Category 1 hurricanes with winds of 75mph. And as you can see from the satellite image above, he is about to rake across the northeastern Caribbean islands. Luckily, he is a minor hurricane, so he should not create significant damage to the islands.
Earl's impact there is pretty much a foregone conclusion. The real question is, where does he go from here? That is a matter for great debate. Though all of the computer model guidance is in fair agreement, there are two issues... 1) The modest differences are critical in terms of potential impact, especially up towards Cape Cod and, 2) the models have, thus far, been awful - way too far east... Earl has gone far west of almost all early projections. Here's how most of those models look now:
...you can see that, for the most part, these all look generally to be safely offshore. And I can tell you that if you extend these tracks out, due to an incoming cold front late in the week, these tracks would curl more eastward... out off of Cape Cod. So, frankly, these tracks don't look too threatening. Of course, we always make clear that hurricanes are not a point, so the inclement weather from Earl would extend out from his center. However, the west side would be the weak side as Earl moves up off the coast. Given that fact, combined with the distance most of these models keep him offshore, it would be safe to say that there would only be a small impact, other than heavy surf.
However, besides the fact that these models have all erred too far east throughout Earl's lifespan, many of them (granted, not all) are based on the same background data of the American's global model (called the GFS - Global Forecast System). The European's model (ECMWF) tracks Earl further west. Here's a shot of where it projects him to be by Thursday night:
...this isn't clear-cut as to whether or not he'd hit New England; it would depend on how sharp his curve to the east is. Unfortunately, due to proprietary reasons, I can't post the image 12 hours later; and the image 24 hours later already has Earl past southern New England. But I can tell you that on Friday morning the Euro model essentially takes Earl right to Chatham, MA (it is basically very near the "elbow" tip of Cape Cod). And though the western side of the hurricane will be the weakest, and the storm will almost certainly be weakening by then, this would likely provide hurricane conditions for the entire Cape and strong tropical storm force conditions for all of southeastern New England..... if this model is correct.
That begs the question... is it correct? Well, here's what the National Hurricane Center thinks:
This looks pretty much like a blend... a little to the west of the consensus of the tracks above, meaning that they're trying to account for the persistent bias of the models and/or paying some respect to the Euro; but at the same time, their track - plus subsequent additional turning beyond day five - probably means that Earl will stay offshore and keep all hurricane force conditions offshore with him. But what is clear is that he will at least be a "threat" to the East Coast (most likely, Cape Cod).
Note that as I write this the latest American model run has been processed. It turns Earl northward more quickly, initially keeping him offshore from the U.S. a bit further. However, he also moves a bit faster, allowing him to move more due northward further, before Friday's cold front kicks him east. That allows him to pass a bit more closely to Cape Cod than the previous run, though he still remains offshore.
The bottom line here is that Earl will likely threaten the U.S. East Coast. But it is still a little too far out to project whether or not his actual impacts on the East Coast will be significant. Clearly, surf and beach erosion will be an issue, but whether or not high winds, heavy rain and storm surge are ever an issue... we'll need to wait another day or so before we can really nail that down.
That's all for now. I'll try to stick around to answer questions in the comments as best I can, but I have a busy afternoon, so forgive me if I miss some or leave the discussion after a while. Oh, and credit is needed... I failed to disclose the above model maps came from Allan Huffman's superb web site.
*UPDATE: 4:00PM EDT Sunday (ok, just before 4PM). This is a pretty simple update, I'm not going to drop in a bunch more images or anything... just wanted to let folks know what the latest is from the computer models, as we've recently had a new round of computer models come in...
The tropical-focused models are all pretty far out to sea. But, to be frank, those have not performed well this season and when extratropical features (cold fronts dropping down, for example) influence the track of a storm, the non-tropical-specific model are just as good (or bad?) as the tropical ones. So, since those tropical models are something of an outlier, I don't think they're correct. Hopefully, I'm wrong... they're all further offshore and would bring little impact to anyone on the East Coast.
As for the others, there's been some decent convergence. The American model is unchanged to slightly west of it's previous track. The Canadian model is well west (and a significant threat). While the European (previously the furthest west) has nudged east. While this represents some convergence, they've actually overstepped, with the Euro model now east of the Canadian and probably a bit east of the American, for example. So, there's definitely still room for debate and error here. But the bottom line is that all of these models show a threat, to varying degrees, to Cape Cod, and a lesser threat to Cape Hatters (Earl may not get far enough west to be an issue there) and Maine (Earl may turn eastward too abruptly to be an issue there). And, as noted, the tropical-specific models are all further east and not very threatening. That's the latest on how the computer guidance lines up. Not much new on his present status... not much new recon data, and Earl looks pretty much status quo on satellite.