The ramifications of the two year Georgia drought expanded yesterday, as the Georgia Environmental Protection Division decided to declare a level 4 drought response for the northern third of the state, while leaving the level 2 watering ban in place for the rest of the state. This map shows the counties affected by the two bans:

Level 4 watering restrictions mean that virtually all outdoor watering is verboten, while the level 2 restrictions limit watering to three days a week on an odd-even basis. The state took the measure primarily because the extent of the drought has reduced the water levels of north Georgia’s to primary water sources, lakes Allatoona and Lanier to the point where there is a real risk of fouling the water supply if the drought continues.

During a year of average rainfall, water levels in Georgia’s large reservoirs such as Lanier and Allatoona tend to drop in late summer and then recover as the winter rains arrive,” said State Climatologist Stooksbury. “But the forecast calls for a dry, mild winter and that could result in serious water supply problems by next spring.

This winter isn’t expected to bring too much relief due to an increase in La Nina conditions, which typically bring warmer than normal temperatures and less than normal precipitation to the southeast. The area specified for the level 4 drought response closely echoes the areas classified as being in exceptional drought conditions in the most recent drought monitor. While rainfall is mitigating the drought in the southern part of the state, a dry August and September in the northern part of Georgia has brought the drought to what EPD director Carol Crouch has called “historic proportions.” September rainfall has averaged around an inch in the northern part of the state, or about 25% of normal.

It doesn’t look like we’re going to get any relief soon. A high pressure system over the southeast is likely to keep us dry for the first two weeks of October, and although the tropics are busy, it appears unlikely that Karen and Melissa will maintain enough strength to reach the southeast coast.

Even if a tropical system were to come and somehow bring a foot of rain to north Georgia, I don’t think that we’re going to see an end to the watering ban until spring, when the La Nina conditions should be receding, and we’ll know how much winter rains filled up the lakes. It took over a year for conditions to get this dry, and it will take a while to get back to normal.

Today’s high temperature of 99 degrees marked the hottest of the summer so far here in Lawrenceville — Atlanta reached 99 on Tuesday, and 100 degrees today. So far, we haven’t broken any record temperatures for the second week of August. That honor goes to the summer of 1980, back when everyone was worried about global cooling, when temperatures stayed above 100 in Atlanta for four days in a row.

Meanwhile, the northern boundaries for heat advisories and excessive heat warnings keep moving further north. The heat advisory for Wednesday stretches from Stephens county in the east, across Hall to Cherokee County, and then, for the western part of the state, north to Chattanooga. While metro Atlanta isn’t in an excessive heat warning, indicating dangerous temperatures, most of middle Georgia is.

On Monday and Tuesday, I recorded a high temperature of 97 degrees, with a heat index of 106. Today’s high heat index was 110, also a record for 2007.

The heat and lack of rainfall isn’t doing much to help Georgia’s drought. A new report by state climatologist David Stooksbury says that while much of the northwest and southwest portions of Georgia are in an exceptional drought—one that occurs only every 100 years. The affected counties include some in metro Atlanta, including Fulton, Cobb, Cherokee, and Douglas. The good news is that now 12 counties in southeast Georgia are no longer considered to be in a drought at all. The rest of the metro area remains in extreme drought, with the situation elsewhere in the state ranging from mild to severe.

The extreme heat and lack of rainfall are causing soil moisture loss of 1/4 to 1/3 inch per day, and if the current weather pattern continues, even the counties that have emerged from serious drought conditions could quickly find themselves in bad shape.

So when are we going to see some relief from the hot and dry conditions? To quote Stooksbury,

“No widespread relief is foreseeable. In August and September, the best hope for widespread drought relief is from tropical weather systems. Without these, we can expect the drought to worsen over the next two months.

“If dry conditions continue, high temperatures during August can be expected to remain in the middle 90s to low 100s across the piedmont and coastal plain. The Georgia mountains can expect temperatures in the upper 80s to middle 90s.”

We’re almost two months into the official hurricane season, which runs from June 1st to November 30th, and so far, we’ve had only two named storms. Given the various predictions for between 13 and 17 named storms, it may seem to some that we’re not going to make it.

Keep in mind that the strongest part of the hurricane season is from mid-August to mid-October, when the Atlantic Ocean is at its warmest. With the exception of 2005 and 2003, when we had seven storms by the end of July, for the past ten years, we’ve seen two tropical storms each year before August 1st, except for 1998 and 2004, when there weren’t any storms at all in the first two months of the season, so we’re on schedule.

The approach of the strongest part of the hurricane season brings a reminder from the Georgia State Climatologist David Stooksbury that Georgia could be severely impacted should a Katrina-like storm hit the coast. In an article posted yesterday on the Georgia FACES website, Stooksbury reports that UGA students created a model of the storm surge from Hurricane Katrina, and then projected it along the Georgia coast, where it would cause a 20-30 foot storm surge.

“A storm surge of this magnitude would wash over the barrier islands and lead to massive flooding along the coast. Almost all of Georgia east of I-95 will be under water with a category 3 hurricane. Areas west of I-95 will see major flooding, too.”

The article also explodes some Georgia hurricane myths, and offers advice on preparedness.

Next week brings updates to the hurricane forecasts by the National Weather Service and Dr. Gray’s team over at Colorado State University, and it will be interesting to see what changes, if any, we see in the predictions.

Dr. Gray has written an op-ed article for this morning’s Wall Street Journal examining if the increases we’ve seen in the intensity of hurricanes recently is being caused by global warming. He compares two long term periods from the early 20th century and late 20th/early 21st, and concludes that the number of landfalling hurricanes in the US declined, despite the increase in carbon dioxide in the air.

Instead of following the politically correct line on global warming, Dr. Gray analyzes the patterns of ocean currents and salinity in the Atlantic over time, and concludes,

“The warming theorists — most of whom, no doubt, earnestly believe that human activity has triggered nature’s wrath — have the ears of the news media. But there is another plausible explanation, supported by decades of physical observation. The spate of recent destructive hurricanes may have little or nothing to do with greenhouse gases and climate change, and everything to do with the Atlantic Ocean’s currents.”

If you’re not a Wall Street Journal Online subscriber, you can read the article via Google News. Click this link, and choose the article “Hurricanes and Hot Air”.

This morning’s AJC front page features an article highlighting the possibility of 100+ degree temperatures this summer due to the drought. Somewhat skeptical due to their previous story predicting high temperatures, I found the article written by the Georgia’s Climatologist, David Stooksbury, who does indeed tell a tale of worsening conditions, and warm summer temperatures.

Stooksbury says that extreme drought conditions have expanded into 104 of Georgia’s 159 counties, compared to 95 counties back in early June, when tropical storm Barry brought some relief to the southeast part of the state. Barry’s benefits are fading quickly however, and Stooksbury echoes the predictions of others when he says that to break the drought conditions, we are going to need some tropical storms.

As you can see from the soil moisture anomaly map above, soil moisture levels are below 5% across much of north and west Georgia, indicating dry conditions normally seen only five times in every hundred years. Even with the rains from Barry, the southeast part of the state is seeing moisture levels expect only once out of four years.

While the lack of rain is taking its toll on your landscape, the drought is about to take a bite out of your wallet as well. Quoting Stooksbury,

“If dry conditions continue, high temperatures between 100 and 105 degrees Fahrenheit could become common in the piedmont region of Georgia. Highs between 103 and 108 could be common in the coastal plain. Even the immediate coast and the mountains could have temperatures in the middle 90s.”

So, with the best hope for drought relief being tropical weather, what’s happening with the climate? In March, NOAA predicted a change to La Nina Conditions this summer, which would point to a stronger than normal hurricane season. However, the sea surface temperatures which determine if we are in a La Nina or El Nino pattern haven’t cooled down in the central Pacific Ocean as much as predicted, and the Weather Service now says that La Nina conditions probably won’t develop until early fall.

If that’s true, then this year’s predictions of more hurricane activity than normal may be overdone. We’ll just have to hope that whenever tropical storms arrive, Georgia becomes the beneficiary of the rainfall.