The heat wave continues in Georgia, with no early end in sight. Friday, August 10th, the thermometer rose again to 103 degrees at 5:29 PM, breaking the previous record for the day of 97 degrees, set in 194. Here in Lawrenceville, the temperature broke 100, although it wasn’t quite as hot as yesterday (like someone would notice).

The three day string of 100 plus degree temperatures is the first time since July 27-29, 1993 that Atlanta has been over 100 for so long. The 103 degree temperature recorded Thursday and Friday is the warmest it’s been since 1980, when the temperature in Atlanta hit an all-time record high of 105 degrees on July 17th, 1980—my third week in Georgia.

The Weather Service has issued another heat advisory for Saturday. Temperatures are likely to stay extremely hot through the middle of next week, when we get a cool spell, with highs only reaching the low 90s.

The heat wave in Atlanta continues. Today’s high temperature of 103 degrees recorded at 12:46 PM at Hartsfield-Jackson airport beat the previous record of 101, set back in 1980. Meanwhile, here in Lawrenceville, the temperature on Thursday also crossed the century mark, to 101.5 degrees, the highest temperature I’ve recorded since I started keeping records in 2002. It could be worse…you could be playing at the PGA Championship in Tulsa, Oklahoma, where it’s currently 97 degrees with a heat index of 105, and expected to stay very warm.

Speaking of records, Brooklyn, New York recorded its first-ever tornado on Wednesday morning—one of three to hit New York City since recordkeeping began. The F2 storm, along with the associated torrential rainfall ground the NYC morning commute to a halt, flooding subways and stalling buses. Central Park recorded 2.5 inches of rain, while 3.47 inches of rain fell at Kennedy Airport in Queens.

With all the heat and drought in Georgia, we could certainly use some of the rain that fell on New York yesterday, and the Weather Service has come through with its updated hurricane forecast. Similar to last week’s predictions by Dr. Gray, the Weather Service is still calling for a stronger than normal season, but has dropped the number of storms by one from its original forecast.

The prediction now is for 13-16 named storms, instead of 13-17, and 7-9 hurricanes, rather than 7-10. The number of predicted intense hurricanes remains at 3. Overall, there’s an 85 percent chance of an above normal season in 2007. Forecasters say that they are more confident of their prediction now because of a favorable climate leading to storm development.

As the above chart shows, the peak of the tropical season isn’t until after Labor Day. Typically, there are one or two storms during June and July, and things don’t really start to pick up until mid-August.

This year’s heat wave in North Georgia is one for the record books. Wednesday’s high of 100 degrees in Atlanta was the first time the temperature broke 100 degrees since August 18th, 2000, when the thermometer reached 101. Wednesday morning also saw a record all time high minimum temperature of 82 degrees at Hartsfield Airport — one degree higher than the previous record, set in 1879 and 1980.

Wednesday’s high of 99 degrees set a record high for August 8th in Gainesville, GA. In Athens, Tuesday’s high of 101 tied a record set in 1980, and Wednesday’s high of 102 broke the previous record of 101, also set in 1980. Macon’s high of 102 on Wednesday also broke the 1980 record set there.

This week also saw another record set for Atlanta — the driest year-to-date ever recorded. With only 17.24 inches of rain as of August 5th, this beats the previous record of 17.25 inches as of that date, set back in 1914. While other areas of the state are also dry, none are in the top five driest years to date. The map to the right shows the latest drought areas in Georgia, as of August 7th.

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.”

Despite a relatively cool July —the mean July temperature was actually cooler than the mean June Temperature, both here in Lawrenceville and in Atlanta— it looks like August is going to be our hottest month of the year.

The short range, medium range, and long range forecasts are all calling for warmer than normal temperatures, and it looks like we may not get much rain to help out, at least until the middle of the month.

Temperatures will be approaching the 100 degree mark all this week in North Georgia. To make things worse, we’ll likely be seeing high dew points as well. That means that the humidity will be approaching the unbearable range. Take a look at the forecast dew points in Georgia for 2 PM Thursday:

If this forecast validates, we’ll see the heat index above 105 degrees, the danger level, several times this week.

Ultimately, it’s the moisture in the air that determines how we feel when we go outside. Although relative humidity is the measurement most people use to measure moisture content, the dew point temperature can provide a better measure of how uncomfortable conditions are. When the dew point rises to near 70 or above, most people are unlikely to want to be outside for very long.

The heat index also measures the apparent temperature. For more detail, take a look at this table showing the relationship between relative humidity, temperature, heat index, and dew point.

The reversal from the cool and wet July conditions to the hot and dry conditions for August isn’t going to do much to help the drought conditions in Georgia. Over the last month, the drought levels in Georgia haven’t changed very much. While the rain has kept lawns green in the short term, we will see a quick return to brown lawns without more rainfall.

As I’ve said before, tropical weather will probably be the key to breaking the drought. Despite the relatively quiet season so far, the latest forecast by Dr. Gray at Colorado State University is still calling for an above average hurricane season. The researchers are predicting 15 tropical storms for the season, down 2 from their May forecast, and eight hurricanes, down from nine in May. There’s also an above average chance of a major hurricane striking the US coast.