Erin a weak fish; 92L Texas-bound?
When I blogged yesterday about Tropical Storm Erin in the far eastern Atlantic and "Invest 92L" (potential future T.D. Six/T.S. Fernand) in the Caribbean, I wrote that neither storm looked like a particularly serious threat to the United States for the time being. That's become even more true in the ~22 hours since. Far from strengthening en route to becoming a 60 mph storm, as the NHC forecasted yesterday, Erin has become a "skeletal cloud swirl" and appears increasingly likely to dissipate -- becoming yet another sacrifice, like Chantal and Dorian before it, to the "God of Dry Air," with an assist from that pesky Saharan dust. Dr. Ryan Maue illustrates:
Moreover, Erin now appears highly likely to be a "fish" storm, staying well out to sea. The official forecast track no longer calls for a "left turn" late in the forecast period -- just the opposite, actually. And the NHC track is actually "south of model consensus," meaning most models are taking Erin even further "right" and safely out to sea.
Below is a helpful illustration of this concept, again from Dr. Maue. The thick lines at the bottom ("OFCL" and "OFCI") are NHC forecast tracks from late yesterday.
NHC wasn't buying the NCEP ensemble suite solution at 18z. pic.twitter.com/YZZyBPIwT3— Ryan Maue (@RyanMaue) August 16, 2013
Much closer to home, Invest 92L (our so-called "proto-Fernand," though it may never get there) looks mighty disorganized as it emerges over water in the Gulf of Mexico this morning. The low-level center is completely exposed, and most of the thunderstorm activity remains over land, away from the center. 92L still has a fighting chance, to be sure -- NHC gives it 50% odds of becoming a tropical cyclone in the next 48 hours, and 60% in the next five days -- but right now, I wouldn't bet on it. Brian McNoldy elaborates:
[T]he surface circulation is devoid of deep convection, and a strong upper-level low to its north is introducing hostile vertical wind shear. ... Since it is now reduced to just a low-level circulation, it should track more toward the west-northwest, rather than turning toward the north. This shifts the longer-range landfall location to Texas or northern Mexico... but, "landfall" makes it sound more significant than it really is. Wherever it goes, its biggest impact will be heavy rain -- perhaps not even that!
McNoldy does note that a more westward track could help allow 92L to eventually spin up into something, since it will stay further away from that upper-level low producing the wind shear that's presently hindering it. But even if so, the "current 'worst case' model...still isn't TOO bad." That model, the HWRF, shows a Category 1 hurricane approaching Brownsville, Texas on Tuesday. (You can see a map of this scenario in McNoldy's blog post.) This is "not a likely solution," McNoldy says, noting that "other models are less bullish."
In any case, the New Orleans/central Gulf scenario appears to be pretty much off the table now, with virtually all models showing 92L heading toward either Texas or Mexico. Here's a map from Hurricane Analytics showing the latest predicted tracks for both 92L and Erin from a bunch of the more reliable computer models:
Bottom line, the trend right now is moving away from a significant U.S. threat from either of these storms. Erin, we can pretty much write off at this point, barring something unforeseen. 92L still bears watching, but there's certainly no cause for alarm, hype or #PANIC at the moment. Far from it.
Last but not least, there is increasing chatter about that wave over Africa that I mentioned yesterday, the one that might be the real "proto-Fernand" if 92L never gets its act together (or "proto-Gabrielle" if it does). The European model depicts this scenario, nine days from now:
Interesting look at the long range EURO model. This is the wave after Erin that will have to be watched late August.. pic.twitter.com/vqz3OsoaX8— Eric Burris (@ericburris) August 16, 2013
More broadly, Joe Bastardi sees a "classic US threat pattern evolving in coming weeks," above average even for the impending climatological peak of the season. Bastardi points to the African wave as perhaps the forerunner of this threat pattern:
Dry air will try to hold it down,but dry in late Aug, Sept is still moist enough to rock. Wave train coming to life pic.twitter.com/Xq41Uas7IJ— Joe Bastardi (@BigJoeBastardi) August 16, 2013
Again, stay tuned. I'll update this blog as warranted, and in the mean time, follow me on Twitter for the latest on the tropics... and politics... and college football... and rants against the NSA... etc.