Atlanta Water Shortage

With Hanna zooming past the east coast, we can turn our eyes to the next possible rainmaker - Hurricane Ike.

Hurricane Ike is a category 3 hurricane as of this writing, and early tracking suggests it might thread the needle between Florida and Cuba and come up the west coast of Florida.

On that track, it could very easily end up bringing Georgia some much needed rain.  Alternatively, if it follows Hanna but as a larger storm, it could at least brush Georgia.

In any case, Ike is the next big system in the area - what are your thoughts?

For a while, it looked like we might be right about Hanna bringing us some rain — turns out we’re wrong.  All of the latest models now show Hanna hitting in the Carolinas and then shooting off to the northeast.  We’re not likely to get much of anything out of it.

In the meantime, Lanier has slowly been dropping this month; down about an inch so far.  Certainly not bad, but that pace will start to accelerate as the ground begins to dry up from Fay.

Maybe Ike or Josephine will show us some love…

Being the first day of the month, it’s time for our monthly status chart and things are looking better!  Fay certainly did a lot of good for us.  Rather than drop 2.5 feet like we did last August, the lake actually rose.

The bad news is that we’re still in rough shape.  Today is the lowest the lake has ever been on September 1st, which is the kind of record we’re setting every day still.  The key is whether the lake will plummet over these next few months like it did last year.  The extra moisure in the ground and the threat of more heavy rain (Hanna?) tend to point to good news, but you never know.

Last September the lake dropped by over three feet (1061.77 down to 1058.73).  What do you think it will do this year?

There are a lot of good tools out there to help you track the various storms using Google Earth and/or Google Maps.

• Various tools provided by Google Earth Blog.
• Hurricane tracker for Google Earth, from Google Earth Hacks.
• A whole bunch of Google Maps tools, from Google Maps Mania.

I tend to go back and forth between the Earth-based and the Maps-based tools.  I love the tilting/rotating/etc fun in Google Earth to get a great look, but the convenience of Google Maps is tough to beat.

Are there any tools you’re using that you’ve found particularly helpful?

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.

For the last few days, most storm models have been showing Fay either missing us completely or just giving us a few bands of rain.  However, now we’re starting to see some models that show the potential for some substantial rain.

The photo at right shows the potential rainfall for the six hour period starting at 2pm Saturday.  Based on that, we could see 3-4 inches in that timeframe, plus some rain before/after the six hour window.

The next few days should start clearing it up either way.

(via Lawrenceville Weather Blog)