T.S. Erika

Well we did get "Erika" named obviously the other day. My thoughts then were that if this system were able to survive, it would be a potential threat to the Southeast / Florida, and I think that theme still applies. This discussion will be brief due to time constraints, but despite Erika's lack of organization, one cannot ignore how persistent the deep convective blob has been to the east of the seemingly erratic / elongated center of circulation. I cannot recall seeing such persistent convection in such a disorganized feature, which I think speaks volumes as far as how decent this storm could have been with just a little better environment. I think more attention needs to be focused on shear at levels other than the standard 200mb-850mb level when doing analysis. It is clear there has been shear, even though the following map shows a shear pattern that while not ideal, isn't the worst by any means either.













Now, from the same site, look at what you see when only looking at mid level shear.

The color scheme obviously is different, but regardless of what anyone tell you, this makes it clear that there has been detrimental shearing going on (duh... when LLC and MLC cannot co-locate, that is typically why), just more focused in the mid levels.

So what about the future? Well, I think this still has a tough road ahead, as to me the shear pattern doesn't look all that great ahead of it the next few days, but it's not so bad to prevent the storm from growing some if the LLC can reform under the persistent deep convection. If this does not occur, the storm may stay on a westward path and face possible death by Hispaniola. A reforming would allow a farther north path and a much better chance at survival, perhaps even substantial growth if it can reach the Bahamas in about 4 days, when shearing should be less. Model trends have come north versus yesterday overall, though I think the GFDL and HWRF are way too agreessive on intensity.

Bottom line, if we don't get the LLC under the deep convection, Erika is in trouble. If we do, it still has a fight for a few days, but could get going more if it survives the next 3 days and winds up in the Bahamas, in which case there would actually be a hurricane threat for Florida or somewhere a up the Southeast Coast. The next 24 hours should tell us a good deal more in order to make a better assessment.

With Danny Gone, Eyes Turn to Next System

So Danny was essentially a non-event, which wasn't a surprise, but I had figured it would keep its "named" status longer than it did, even though it wasn't a purely tropical system. In any case, he's gone, so we're left with tracking the system east of the Lesser Antilles, which looks close to if not already at tropical depression / storm status at this time, so a classification could take place by NHC later today or tonight. The environment through tomorrow or maybe Wednesday could be good enough for some steady development, though it is close, as it will be on the eastern edge of a pretty hefty shear zone. After mid-week, the environment doesn't seem to be very favorable to me, as the upper low currently causing the shear probably doesn't move away faster than the storm is moving, and add to this the fact that by the weekend, there may be a piece somewhere in the southern U.S. or Southeast left behind in the wake of the current cool trough to also add some shear to the mix. It seems that some are of the opinion that if this system survives and gets toward the Bahamas this weekend, then it is off to the races intensity wise, and I'm not sure that is the case. Mind you, that does NOT mean it can't be a hurricane at all, but comparisons to storms like Andrew, or even 2004's Frances seem premature by a long shot, as the pattern to me does not look nearly as favorable, as both of those storms had better upper air ridges to the north, noted by the 588 height line at 500 mb extending way farther into the U.S. Point here is that on the edge of ridges, you have to watch these little "garbage" upper air features that can dance around, and that needs to be considered when trying to figure out future intensity as well as of course track. I have posted the European model shear map at day 6 as an example of this. Despite a decent upper ridge in western Atlantic, there is a little weakeness on the western side, and as you can see on the bottom left image, assuming we do have "Erika" in the Bahamas this weekend, the environment is not ideal. Now, you say, well the model could be dead wrong. Sure, it very well could, but most models generally agree on the position of the ridge, which means we have to watch for these subtle weaknesses given the strong trough departing the East.

So all of that said, first off I'm not sure if this thing will survive the trek into the Bahamas (I'm assuming that is the general direction it should go, as the ridge should keep it from escaping out to sea before getting that far), but if it does, the enviroment to me does not scream major hurricane, but at the same time, there is the risk of downplaying it too much, as a minimal hurricane still is a formidable foe if you have to deal with it, and this system will have a hard time "escaping" out to sea, so the odds favor either 1) getting torn apart by shear in the coming days, or 2) a move toward the U.S, probably Florida focused, so it does bear watching of course. My discussion here is more geared toward some of the rumblings I have heard about this possible being the next "big one". I think it has quite a fight on its hand to get to that status. In any case, it will be interesting to track, as the fact that it has been slow to get going has allowed it to be more of a potential player than I figured it may be from last week.

Danny Update... Next Feature Flares Up in Eastern Atlantic

Danny still doesn't look the greatest, though to me this isn't a surprise, as I've always felt a minimal hurricane was the highest potential max intensity for this thing all along. The center of circulation still has not seen convection wrap around it, and it wouldn't be a shock to see it reform farther east where the convection is deeper, which would mean the risk for an official landfall is much less. Even with the track I had, which was near Hatteras to Cape Cod, this was not really gonna be a big deal where most people live in the I-95 corridor, as rain from interacting with the incoming cool front was really the biggest "threat". However, it does look like the track I had will need to be nudged a bit to the east, and at this point, any landfall is probably relegated to around Nantucket and that's about it. All in all, this will be a storm that got talked about quite a bit by some, but will go down as something that in the grand scheme of things is quite insignificant.

But fear not all you tropical enthusiasts, as the next system may be forming in the eastern Atlantic, as we do have a wave that has flared up nicely, and is in an evnvironment that right now isn't too bad, so in the next few days, we could have Erika on the map. My guess right now is that this will have a hard time ever being a threat to the U.S, given that we will likely have at least one weak upper low dancing underneath the Atlantic ridge, which will probbaly act to guid this storm north of the Lesser Antilles, and then it would probably get steered back out to sea given the strong upper trough headed into the eastern U.S. next week, which probably will split and send a piece tailing into the Southeast. But obviously we're talking a long way out here, and plenty of time to watch this one.

We Have Danny!

The system discussed yesterday has just been updragded to Tropical Storm Danny, as it has finally developed an established low level circulation, and the shear pattern has improved quite a bit versus 24 hours ago. The center of circulation is not embedded underneath the deepest convection, which until that occurs will limit how fast this can ramp up, but it's a big improvement. As for the future of Danny, I don't have a lot different to add to what I stated yesterday. My guess is that the strongest this can get is a category 1 hurricane, and my best guess at track is still toward eastern North Carolina (I think the upper ridge holds this farther west than the GFS model and it's cousins, the NHC hurricane models and GFDL), affecting Hatteras the most, then moves northward along the East Coast, perhaps making another "landfall" (assuming it is still a tropical entity, which I think it should be, enough to keep classified as Danny... we'll see) in southern New England as the next upper trough is focused back in the Midwest this weekend.

While not a "major" system, it could make things interesting right along the coast, though into the big cities of the East, I still think heavy rain is really the only notable threat here. I guess the track I have laid out would put New York and Boston at a higher risk for more periods of tropical storm force wind gusts, but still there I tend to think rain is a bigger issue than wind (keep in mind I mean the metro areas, not right along the shores of Long Island or over to Cape Cod).

This also puts us actually a little ahead of schedule for the 4th named storm, which typically occurs around September 1st... interesting given the slow start to the season!

The Hiatus Is Over - Tropical Threat to East Coast?

Obviously it has been a long while since I posted anything here, mostly due to welcoming my second son into the world at the end of June, and obviously being pretty occupied on the home front since then. And of course there have been the usual commitments to the real job as well. But I am going to try and get back in the mode of updating periodically here, as we are headed for the more exciting time of year for many weather enthusiasts, which is the run up to the winter season!

But for now, it is still summer (which FINALLY came to the eastern U.S. this month), and we are still in tropical mode as well, even now with a threat to the East Coast perhaps! All eyes are on "Invest 92", an area of disturbed weather north - northeast of the Lesser Antilles, which is heading to the west-northwest currently. As of now, conditions are not all that favorable for development, at least not very quickly, but should improve over the next day or two, and I do think we'll have Tropical Storm Danny out of this. Now, where does it go? Well if you believe the U.S. models, it will turn harmlessly back out to sea. But other models say not so fast, and with good reason in my opinion. The GFS model seems pretty quick to develop this, and perhaps a bit north of where the true low level center will eventually wind up. Because a more developed system can be tugged north by any weak upper features, the GFS, by virtue of being faster with development, sends Danny-to-be off into the westerlies much faster, and stays well offshore. But given that the shear is not that favorable right now, I'd lean toward a slower development curve, and a path farther west. A pretty potent trough will dive into the Midwest this weekend, and that should mean we have enough ridging downstream in the western Atlantic, which also leads me to believe a farther west path, closer to the other modeling. This says to me that "Danny" has a much greater shot to impact the East Coast than Bill ever did, though I don't think this system gets as strong. It could organize enough to reach hurricane status, but the incoming trough should start adding enough shear to make it a tropical storm up the coast, so not the best of weekends at the coast, but where most people live in the I-95 corridor, it is probably more a rainmaker. What else will need to be looked at is the potential for the storm to interact with the incoming front and enhance rainfall even more, perhaps leading to some flooding concerns.

So the bottom line is that we should see Danny out of this, and my best guess right now would be a storm moving close to or into eastern North Carolina this weekend, then northward up the coast, probably as a tropical storm, presenting heavy rain concerns up the eastern seaboard, with most of the significant wind issues right along the coast.

First Tropical Storm of Season?

Well we are almost through the first month of hurricane season, and so far have not had much to discuss. This is not entirely unusual, as many Junes do in fact wind up quiet. But we have a system now in the western Caribbean Sea that I think has a shot at becoming our first named storm of the season. The first image below is the satellite picture of the Caribbean as I type this, and I have posted the link for this above the image, since the image itself shown here is not one which will update, so by the time you read this may be old!

In any case, it looked better earlier, but is not in an ideal environment right now to develop. It should continue to drift northwest, perhaps passing just east of the Yucatan Peninsula of Mexico this weekend. Wind shear will be gradually subsiding some as well, so it is possible that by Monday it is able to organize into Tropical Storm Ana.

Where would it go from there? Well, a fairly strong trough will dig into the eastern half of the nation, which probably has enough influence to turn whatever is in the Gulf toward Florida. This path would not be one that would allow any storm to strengthen much though, as wind shear is forecast to increase in the northern Gulf by Tuesday in response to the incoming eastern trough. See the second image below for the forecast shear, valid Tuesday evening (courtesy of the fine folks at MDA!). Values greater then 20 knots are certainly unfavorable. This means that, while possibly holding on to "named storm" status, this would be pretty much just a rainmaker for Florida, as it could not possibly intensify much with this pattern in place.

The other option is that the trough does not pick up whatever is there early next week, which would probably mean a path more toward south Texas or Mexico given the ridge that would be to its northwest. But the environment could be a little more favorable for development on this course. I'd rate this as less likely than option one discussed above though. At least we have something to watch!

Carribean Satellite:

http://www.ssd.noaa.gov/goes/east/carb/avn-l.jpg

Record Heat in Houston!

While June has not been a hot month at all for many locations, the heat has certainly cranked down here in Houston. The last 2 days have climbed above 100, and should again today. In fact, yesterday's 104 degree high set the all-time June record here. Then we have this morning's low of 84, which also broke the June record for highest minimum, and tied the all-time mark for any month. The stat of the day: Our low down here this morning was hotter than the hottest high in New York City all month long! It's a neat stat, but should not be valid after tomorrow, as New York City should finally get above the 84 mark.

What was odd about the 104 here yesterday is that we were able to achieve that without a 500 mb ridge of at least 5940m in intensity. That is hard to pull off, but the fact that much of this area has seen no measurable rain for 31 days is helping that, as with no moisture in the ground, all of the sun's energy goes into heating the air rather than some of it getting used up in evaporating moisture.

Looks like, barring something strange, this will be a top 3 hottest and top 3 driest June on record here. Hopefully we won't follow the trend of the other 2 hottest Junes on record, being 1980 and 1998, and July of those years also went on to be hot (especially in 1980). Unfortunately for those of us down here though, it is hard to forecast anything other than "above normal" for Texas in July given the pattern we have in place.