Will Isaac Occupy Tampa?
[LATE WEDNESDAY UPDATE: Here's my latest post.. Or just go to the Weather Nerd homepage.]
Let me begin with the standard caveats about uncertainty. 5-day track forecasts from the National Hurricane Center, while steadily improving year by year, still have an average error of around 250 miles. (That means, of course, that sometimes they’re even more wrong than that.) 5-day intensity forecasts are even shakier. That said, take a look at where the NHC believes a Category 1 hurricane named Isaac will be next Monday, which happens to be the first day of the Republican National Convention in Tampa, Florida:
Yikes.
Isaac is presently a Tropical Storm with winds of 45 miles per hour, and its inner core actually seems to have weakened overnight. But “the overall structure of the storm is improving,” according to the NHC’s 11am EDT discussion, which suggests its long-term prospects may be improving.
But with Tampa on everyone’s mind, the focus is on the track. The NHC sounds pretty confident about the first 48-72 hours of the forecast, bringing the storm into or near Hispaniola. After that, despite the relative consistency of the NHC forecast tracks since Isaac formed yesterday morning, there is more uncertainty — indeed, an increasing amount of uncertainty this morning, according to the NHC:
AFTER [48-72 HOURS]…THE [RIDGE OF UPPER-LEVEL HIGH PRESSURE SITTING ACROSS FLORIDA AND THE SOUTHEASTERN U.S. TO ISAAC'S NORTH] IS EXPECTED TO WEAKEN SOMEWHAT AS A MID/UPPER-LEVEL TROUGH MOVES ONTO THE EASTERN UNITED STATES. THE MODELS DIVERGE ON THEIR FORECASTS OF THE RIDGE. THE ECMWF [EUROPEAN COMPUTER MODEL] DOES NOT BREAK THE RIDGE…AND THUS FORECASTS A MORE WESTWARD MOTION NEAR OR SOUTH OF CUBA. THE CANADIAN AND NOGAPS HAVE A LARGE BREAK IN THE RIDGE AND TURN ISAAC NORTHWARD EAST OF FLORIDA. THE UKMET HAS A BREAK IN THE RIDGE OVER THE NORTHERN GULF COAST AND MOVES THE CYCLONE OVER THE FLORIDA PENINSULA. THE GFS SHOWS A BREAK IN THE RIDGE EAST OF FLORIDA…BUT FORECASTS ISAAC TO BYPASS THE BREAK AND MOVE NEAR THE SOUTHWEST COAST OF FLORIDA. THIS DECREASED-CONFIDENCE PORTION OF THE FORECAST TRACK IS SHIFTED A LITTLE WEST OF THE PREVIOUS TRACK TO LIE NEAR THE CONSENSUS MODELS.
A “little to the west of the previous track” means directly aimed at Tampa, at least for the moment. But more important is that “decreased confidence” language. Forecasters really aren’t sure what’s going to happen after Isaac hits, or brushes, Hispaniola on Friday. This thing could wind up staying south of Cuba, and perhaps eventually slamming the Yucatan Peninsula of Mexico. Or it could come up the Eastern Seaboard… or head out to sea. A lot of possibilities remain on the table. “From Mexico to Maine,” as I keep saying.
The next couple of days will be critical in firming up the forecast track. By the end of the week, we should have a much better idea where Isaac is likely headed, and whether the RNC needs to seriously think about activating its contingency plans. (I, for one, hope that if there’s a need for an evacuation, Governor Chris Christie is the one to announce it. “Delegates, get the Hell off the floor!“)
In the mean time, my advice would be for everyone to watch closely, but certainly do not #PANIC. There’s a lot of time yet, and many miles between Isaac and the coast. That said, Tampa-bound “Occupy” protesters may want to invest in some raincoats and umbrellas, purchased from the evil multinational corporation of their choice. 
I’ll update this blog as often as I can (i.e., as often as my day job permits) in the next few days. For more frequent updates, you may also want to follow me on Twitter, @brendanloy, and check my timeline for the latest. I tweet a lot about non-hurricane-related topics, too — WARNING: my politics are center-left… though some of my best Twitter friends are conservatives! (heh) — but the more Isaac becomes an imminent threat to the U.S. mainland, the more Isaac-focused my tweeting is likely to be.
Of course, you should check the National Hurricane Center website for the latest official information. Full advisories, with updated forecast tracks, come out at 5am, 11am, 5pm and 11pm Eastern Time.
Also keep an eye on Dr. Jeff Masters’s blog. He usually only updates once or twice a day, but his updates are thorough and excellent. Here’s some of what he wrote this morning:
Florida, Cuba, Jamaica, and the Bahamas are all at high risk of receiving hurricane conditions from Isaac. The latest set of 06Z (2 am EDT) model runs for Isaac are fairly unified for the coming three days, showing a westward track to a point on the south coast of Hispaniola. All of the models then predict a more west-northwest track across the island and into eastern Cuba, as Isaac responds to a trough of low pressure over the Southeast U.S. Most of the models then predict a path for Isaac along the spine of Cuba, then into the Florida Straits off the coast of Miami by five days from now.
A notable exception is our best-performing model, the ECMWF, which keeps Isaac just south of Cuba, and takes the storm more to the west between Jamaica and Cuba on Saturday, then into the Yucatan Channel between Mexico and Cuba by Monday. However, this model is keeping Isaac weaker than the other models, and thus predicts the storm will have a weaker response to the trough of low pressure over the Southeast U.S. If the official NHC intensity forecast is right and Isaac becomes a hurricane on Thursday, the more southerly track of the ECMWF is not going to verify, and Isaac will spend considerable time over Cuba on Saturday and Sunday. Where Isaac pops off the coast of Cuba will be critical in determining its future path and intensity. Some models predict a more easterly exit point, allowing Isaac to move up the east coast of Florida, and potentially make landfall in the Southeast U.S. The latest 06Z GFS model run predicts a more westerly track, which would potentially allow Isaac to move up the west coast of Florida towards Tampa.
Here’s what that 06Z GFS model looks like as of early Wednesday morning, per the excellent Weather Bell Models by Dr. Ryan Maue, who you should also follow on Twitter:
Gulp. Okay, back to Dr. Masters:
Keep in mind that the average error in a 5-day forecast is 260 miles. The two most recent runs of the GFS model, at 00Z and 06Z (8 pm and 2 am EDT), gave positions for Isaac that were about 250 miles apart–the earlier run putting the center near West Palm Beach, and the more recent run giving a location between Key West and Havana, Cuba. While passage over the high mountains of Hispaniola and then Cuba will substantially disrupt Isaac and probably reduce it below hurricane strength, the storm is quite large, and should be able to re-intensify once it emerges over the Florida Straits. Waters will be very warm, near 30°C, wind shear is predicted to be light, and forecasts of the upper-level winds show the possibility of an upper-level outflow pattern very favorable for intensification. If Isaac spends a day over water, that should be enough time for it to intensify into a Category 1 hurricane, and if the storm takes a longer 2-day track over water up either the east or west coast of Florida, a Category 2 or stronger storm is possible.
Isaac is a threat to affect Tampa during the Republican National Convention, August 27 – 30, and the official NHC forecast now has Tampa in the 5-day cone of uncertainly. The latest 11 am EDT wind probability forecast from NHC gives Tampa a 9% chance of receiving tropical storm-force winds for the 24-hour period ending on the morning of first day of the convention (Monday). I blogged about the climatological chances of a hurricane causing an evacuation of Tampa during the convention in a post last week, putting the odds at 0.2%. I put the odds of an evacuation occurring during the convention in the current situation at 3%.
P.S. Oh — and Tropical Depression Ten has formed behind Isaac in the central Atlantic. It’s likely to become Tropical Storm Joyce soon. Could proto-Joyce become the second half of a one-two punch, hitting Florida near the beginning and the end of the GOP convention? At the moment, that looks unlikely. T.D. Ten is presently forecast to stay safely out at sea.
Oh man I can already see the smug and ironic comments from the left incoming. “It’s an act of God because God hates Republicans”.
“Karma for Katrina”
etc etc…
Any thoughts on the one behind Issac.
Double trouble ? Too early to tell ?
The fact is, on this general track, storms are unpredictable for the US mainland. Until the storm pops over or off of Cuba, the models may agree but they are, in my experience, speculative. Charlie back in 2004 had nice models along a track south of the projected one for Isaac with Tampa lined up for a direct hit for several days. Only late the night before, after shaking off Cuba, Charlie took an unexpected hard right turn to hit Punta Gorda then track up central Florida. Tampa, for all the evacs and prep got a breezy day with a smattering of rain. I was on a ship in Tampa Bay at the time and grew really concerned when the momma cat on the wharf took her kittens, one by one, to higher ground.
On this track, with this steering, everyone in Florida needs to prep but any certainty of where Isaac will cause problems is pure speculation. Until he’s been in the Gulf for a day or so, expect the unexpected.
The ‘occupiers’ might get wet.
It’ll make them smell a little better.
I hope there’s no hurricane, but I hope Tampa gets enough rain to wash the anarchist trash off the streets.
These hurricanes and tropical storms tend to drift quite a bit East of where the predictors maps indicate.
While a concern for the organizers….I wouldnt worry about it too much.
I actually think this will make people more likely to pay attention to the convention. So unless it blows the top off the convention center, it’s a win in my book.
Yes, I hear the Tampa police are working on a soap cannon to clean up the protests.
They might not want to be to smug. Isaac or the one following could track north to rain on their own parade in Charlotte the next week.
Although, if Al Gore is to attend, the Dems may have to contend with a snow storm.
It is way to early to predict where Isaac will end up making landfall. Charley’s predicted path had it passing to the west of Tampa but suddenly Charley made an abrupt right turn and came quickly inland at Punta Gorda south of Tampa and crossed over Central Florida. It arrived in Central Florida quicker than you can say Brian Norcross! I was there! People actually left Tampa to take refuge in Central Florida and unfortunately found themselves in the middle of a hurricane. One thing is that the southeast is having some cool weather at present and cool weather is not conducive to a strong hurricane.
Reality Check: Mitt Romney’s Mormon Faith Will Turn Away Latino Voters?
http://www.youtube.com/watch?v=ZO3HhVOE5As&feature=plcp
I think we need to hype this and stoke the hype and pour gas on the flames as we fan them. The LSM cannot resist a good hurricane story, and this one has the added drama of Mother Gaia launching a mighty blow at those Evil Rethuglicans for all their plans to heat the Earth and raise the level of the oceans, all for corporate greed, when they aren’t pushing granny off a cliff in a wheel chair Mitt The Meany had outsourced to China.
They will forget all about Bleepforbrains Akin, and once a narrative dies they seldom come back to life. You know that given a chance, they will all climb over each other for a chance to stand in front of the Convention in 70 MPH wind and rain and pontificate about poetic justice and other vacuous drivel.
Way better than 5 straight days of Republicans being asked to define “Legitimate Rape”.
So basically, our greatest meteorological minds tell us Hurricane Isaac might hit Tampa or it might not.
And Isaac might be a category X or a category Y storm.
Where’s Willard Scott? I want to hear from him. And does he still have his old Ronald McDonald costume?
Welcome back Brendan! I always enjoy your commentaries since you emerged as one of the most informative and persistently sane weather bloggers during Katrina. I live in Perth Western Australia where we occasionally get the tail end of what are called Tropical Cyclones in the Southern Hemisphere or at least this part of it. But I always have skin in the game with these Atlantic hurricanes. My son and his family live in northern Palm Beach County pretty much due east of the bottom of Lake Okeechobee. I like the predicted track plot that shows all the various predictions separately. It keeps one from getting prematurely fixated on any one predicted outcome. I was with my family during the 2011 Hurricane season when Irene came through. It was headed right for West Palm Beach which smoothly shifted their workforce onto a storm preparation schedule. Home Depot and Lowes broke out their emergency supplies of plywood and rental trucks. We went through the boarding up procedures until Irene veered away not hitting the coast until North Carolina before creating all those epic floods in the middle Atlantic area up into New England. What impressed me most was the depth of hurricane knowledge among South Floridians. Municipal workers, hardware store clerks, the folks next door knew their stuff so we had all the knowledge we needed when we needed it. No one scoffed at the danger. It reminded me of how the Darwin cyclone in the 70s caught that city flatfooted. As a friend who had survived it with his wife and four children in the only room of his house to not be blown away told me – Darwin had not had a serious cyclone in living memory.
The meaning of the name Isaac in Hebrew is “He will laugh.”
Looks like God will be having a good one. Wonder what Pat Robertson will have to say about that?
In addition to the threat of Isaac, the Administration has means of upending the Republican Convention, e.g., an intercession in Syria, diplomatic breakthrough with Iran, etc.
I live in Tampa. I jog in Cat.1 down here. There should be no problem, except people getting slightly wet (which is all to the good with the OWS crowd), unless the storm comes right into Tampa Bay. Even that should not shut down anything, we are very used to rain – even heavy rain – down here.
As someone that has lived in florida for a long, long time and got a direct hit from one, I can say the safest place to be is exactly where the forecasters predict it will hit.
I rather like the idea of a storm, the GOP will be safely inside, dry and comfortable and the raving lunatic leftist radicals will be left to rant in the wind and rain! Well, we will see just how “fair weather” their cause is won’t we.
I’m not planing to attend the Convention, sorry
I could make a stop in Cuba and remain there for a while tho
Currently there is speculation that Isaac might force cancellation of the convention. If that happens, maybe that will ultimately sound the death knell for all future conventions.
Frankly, national political conventions (for both parties) are even more obsolete than the post office. There hasn’t been a truly meaningful one since the 1960s at least. These days they’re just multi-day advertisements for the already anointed nominee, with all events as carefully scripted and choreographed as a pro wrestling match. They serve no legitimate purpose, and therefore should be consigned to the dustbin of political history.
Even worse, conventions disrupt the locals’ lives and commerce*, force the host to spend millions on additional security, and attract the worst elements of society (the massive riots at the DNC in 1968 and the Occutards today). They also provide opportunities for corrupt politicians to further oppress the people. Earlier this year the leftist mayor of Tampa demanded suspension of the state’s CCW laws during the convention — turning the city into a victim-disarmament zone. Fortunately Gov. Scott told him to get lost.
* – The 1992 GOP convention in Houston forced the Astros to embark on a four-week road trip! The Rays got off easy — just a normal seven-day jaunt.