Atlanta Water Shortage

All of the forecasts for Gustav show it getting stronger for the next day or so, then weakening a bit before it makes landfall.  Weather Underground has a great graphic to illustrate why, which you can see on the right.

When a hurricane is over warm water, as it is now, it tends to strengthen.  Over cold water, it tends to weaken.  As you can see from the image, Gustav is expected to track directly over the “Cold Eddy” before it makes landfall.  The more time that Gustav spends over that cold water, the weaker it will become.  Unfortunately, it’s expected to move rather quickly and won’t stay in one place for long.

This map also shows why Gustav has become so powerful over the last day — it’s sitting on top of very warm water.  Intersting stuff.

I feel kind of bad calculating our odds of rain from these storms, due the horrific destruction that they’re likely to cause.  However, thousands of other blogs are covering that angle quite well, so we may as well stick to our roots and look at how these storms might impact our water situation.

Much like two days ago, Hanna still seems to be the most likely storm to bring us some rain.  Gustav will obviously bring a ton of rain, but it will almost certainly stay west of us.  Hanna, on the other hand, could find its way to our area and deliver a good bit of rain.

For a while, it seemed that Hanna might slip through the Florida keys, end up in the Gulf, and then decide where to go.  Now, however, it seems that she’ll make a turn to the northwest and head in our direction.  It’s certainly not a sure thing that she’ll bring us rain, but Gustav is almost guaranteed not to at this point, so that gives Hanna the edge by default.

There are as many as four other storms that are forming right now off the coast of Africa, but it’s far to early to predict if any of them will develop.  For now, all eyes are on Gustav and Hanna.

Gustav is forecast to enter the Gulf, strengthen and then make landfall… somewhere.

Hanna is forecast to move west, possibly strengthening and hitting the east coast.

Which one might bring Atlanta the best chance for rain?

Hanna is a westward moving storm that developed further out into the Atlantic than the normal train of hurricanes that make their way into the Gulf.

Many of these hurricanes get blown north, never hitting or just skirting the coast.  The winds may not be favorable for that right now - if she hits the east coast, she will push in to the west.

If she hits anywhere within a couple hundred miles of Georgia on either side, Atlanta is likely to get significant rain from her. 

Gustav by comparison, will move into the Gulf, and then may move anywhere - west to Texas maybe or as the current forecast suggests, right into to New Orleans.

(My money is on New Orleans because of the irony - the USACE has just reminded everyone that the levees are not fully repaired and will not be until 2011, and my friends in that great city just finished rebuilding their home)

Maybe Gustav will pull east and hit Georgia and Florida. If it doesn’t pull east, Atlanta won’t get a sizable piece of this storm.

So, my money is on Hanna - where do you stand?  Gustav?  Hanna?  Both?  Neither?

We mentioned earlier that Gustav could become a category 3 hurricane before it makes landfall.  Now there’s talk that it could reach category 4 or 5 status.

Accuweather Meteorologist John Kocet says:

“There is nothing in Gustav’s path that will hinder development. There is a strong probability that it will be a Category 3 storm by the time it enters the Gulf, and it has the potential to strengthen into a Category 4 or 5 storm over the Gulf.”

The great thing about Fay is that it was a relatively quiet storm (compared to a major hurricane), but it still brought us some nice rain.  Gustav is likely to cause major destruction, making our water situation seem pretty petty in comparison (as it should).

Below are a few maps from Weather Underground showing the possible path of the storm.  The five-day forecast shows it aiming directly for New Orleans, though the computer models are still quite varied in their predictions.

This will certainly be a storm to keep an eye on, as it could have a major impact on a lot of lives.

The big question everyone is asking: Did Fay “fix” the drought? In a word, no, but it helped.

With the rain essentially gone, the total at Buford Dam over the last few days is presumed to have been about five inches.  The USGS totals only show about 4 inches, but they seem to be having some problems with their system.  Hopefully they can get that fixed.

In terms of the lake, the water has risen nearly 17 inches, from a low of 1053.30′ on Sunday (and Monday) morning, up to a high around 1054.69′ right now.  That was the level back on August 7, so this storm bought us nearly three weeks.

However, this rainfall will benefit Lake Lanier for weeks to come.  The biggest problem facing the lake is the amount of water drained from the lake each day.  Recently, around a billion gallons per day was being released, but that was reduced by nearly 40% on Monday, and will likely be reduced for some time to come because of the excess water downstream.

Next up is Gustav. It’s expected to strengthen into a strong storm (possibly a Category 3 hurricane), but no one has any idea where it might make landfall.  Whether we see any rain from it or not is completely up in the air.  We’ll keep you posted as the storm gets closer.