theweatherprediction.com
[--MAIN HOME--] [--ALL HABYHINTS--] [--FACEBOOK PAGE--]

The Central Georgia Triangle

MIKE FULLER

The Central Georgia Triangle: The Difficulty in Weather Forecasting for Central Georgia Due to the "Wedge" Influence, the Gulf Influence, and the On-shore Flow From the Atlantic Ocean

Central Georgia consists of the city of Macon, located in Bibb county, and the seven surrounding counties which make up the total viewing area for Central Georgia television. The area is known for mild winters, hot summers, and what seems like only about two weeks each of spring and fall. The geographical location for Central Georgia is just that, central Georgia. Macon, the center of the center, is 180 miles inland from the Atlantic east coast. It is about 200 miles northeast of the Gulf of Mexico, and only 150 miles southeast of the Appalachian Mountains in northwest Georgia. The effect these mountains have on weather in Central Georgia is referred to by local meteorologists as the "wedge".

As may be expected, the majority of Central Georgia's weather is influenced by the Gulf of Mexico. It is often said that if you want to know what the weather is going to be like in Georgia tomorrow, look at Alabama today. The gulf flow of warm currents creates warm moist air which pours over the state very easily since Georgia is largely a low, plateau state. The warm waters of the Atlantic flow into the gulf continuing to warm as they flow out clockwise along the coasts of Texas, Louisiana, Mississippi, Alabama, Georgia, and Florida. These warm waters have, over the years, fueled many tropical storms and hurricanes that created severe weather for the southeastern states.

The Atlantic Ocean may not effect Central Georgia as regularly as the Gulf of Mexico, but it can bring more chances of tropical storms and hurricanes to hit the state directly or indirectly during hurricane season. Approaching hurricanes along the lower east coast have little effect on Central Georgia other than rain and winds. The storm system's counter clockwise rotation keeps the strong winds further east. However, tropical storms and hurricanes from the gulf, and those from the Atlantic that come inland and travel up the west side of Central Georgia have been devastating. But, all weather influence from the Atlantic is not from hurricanes. Occasionally, Central Georgia is effected by a sea breeze as cooler air develops over the water and moves in from a high in the northeast. Of course other events must be factored into the effects the Gulf of Mexico and the Atlantic have on Central Georgia. Most disturbances in the gulf and south Atlantic effect the mid state.

Although the Appalachian Mountains cross only the northwestern tip of Georgia, their entire length runs from central Alabama, northeast to Canada. Their geographical presence creates what meteorologists in the mid state call the "wedge", and they say it is the main reason forecasting weather in Central Georgia can be difficult. The Appalachian mountain range is not very high as it goes through northwest Georgia. However, as it stretches through Tennessee, North Carolina, Virginia, West Virginia, and Pennsylvania, heights can reach 7,000 feet. The Appalachians are not as big as the Rockies; they are much older and thus have been "weathered" down over time. But, their influence on weather is still strong... and hard to predict.

Cold air moving down from Canada moves from the northwest approaching Central Georgia. This is a typical cold front for the mid state. Meteorologists can watch the movement of this mass of cold air heading their way which should bring lower temperatures. On occasion, high pressure will set up off the east coast of the United States. The clockwise rotation of the high will usher in a cooler and dryer air mass from the northeast. The Appalachian chain acts as a dam, funneling this air mass into northeast Georgia. This wedge-like section of Georgia can stay in place for several days. As storms roll west to east from Texas to Georgia, their primary fuel is moisture from the Gulf of Mexico. If a wedge is in place, these storms can decay rapidly as they enter the more stable air mass. In a severe weather event, detection of the wedge is crucial. As in many cases, it could determine the strength and duration of approaching squall lines. An example of this could be, if storms enter west Georgia, in an environment with 80 degree temperatures and dewpoints in the mid 60's, the storms should have the necessary fuel to sustain them. But, upon encountering the wedge, these storms can quickly loose strength with temperatures in the 60's and dewpoints in the mid 40's. This can occur in a span of only a few miles.

The wedge can create tremendous temperature differences within the state. Meteorologists can detect the wedge on a surface map when the temperature and dewpoint are drastically lower in the northeast part of Georgia than in the mid state. The wedge makes it hard to pinpoint stability or instability in severe weather occurrences causing meteorologists to "over" forecast. This is not a problem in south Georgia since it is not influenced by the wedge. Thunderstorms moving through Mississippi and Alabama usually make their way into Georgia. These same storms, if headed for Central Georgia can be forced further down by the wedge, or pulled up by the wedge. The storms can run into a cold dry air mass down from the wedge and loose instability having nothing to fuel them.

A good example of the effect the wedge influence can have on Central Georgia occurred on March 1st, 2007. Radar showed mid state forecasters new thunderstorms headed their way. According to their observances, if the wedge was in place, it could have disrupted and shortened the life of the storms. But, in their terms, the wedge broke down. Central Georgia was inundated with severe thunderstorms and small tornadoes from Alabama.

A look at temperature and dewpoint observations will usually demonstrate the influence of the wedge, the Gulf of Mexico, and the Atlantic ocean on Central Georgia. Movements of air masses and storms generally move from west to east. As these events reach the Central Georgia area, they tend to move east, with embedded cells moving northeast. In winter months, the wedge can create difficulty in forecasting frozen precipitation. More often than not, Central Georgia can find itself right on the Demarcation line between what is frozen precipitation and what is not. Thus the forecast, very often, is for a rain, sleet, and snow mix. Although winter weather events are not common in Central Georgia, when they do occur, the wedge effect can make for a very problematic forecast.

The Central Georgia Triangle is not as famous as the Bermuda triangle. Airplanes that fly out of Macon usually come back. Ships never disappear since there aren't any to begin with. But to local meteorologists, the Central Georgia Triangle can be just as perplexing. The public today, has been educated by much more detailed weather forecasts by media such as the Weather Channel. Gone are the days when someone just wanted to know if it was going to rain, or how cold is it going to be today. They have come to expect a much more detailed forecast with reasoning. The Central Georgia Triangle can make this difficult.

Acknowledgments:

Great World Atlas... Charles B. Hitchcock

www.theweatherprediction.com... Jeff Haby

Extreme American Weather... Tim Vasquez

Thunderstorms, Tornadoes and Hail... Peter R. Chaston

The fine group of Meteorologists at WMAZ Television who were willing to talk to me about this subject.