Wedge Keeps Atlanta Cooler Than Normal; Summer Weather Scorecard
If you have looked at the morning weather forecasts over the past few days, you might have noticed that high temperatures did not reach what was predicted. Despite forecasts for the mid 70s today, the high in Lawrenceville didn’t make it above 68. On Tuesday, the high was 75 in Lawrenceville, and 80 in Atlanta.
Blame the whole thing on cold air damming, popularly known as the wedge effect, where high pressure at the surface is trapped by the mountains and is overrun by lower pressure. We’ve got a high located near the Georgia/North Carolina border that is interacting with lower pressure arriving from the west. Since air at high pressure is heavier than air at low pressure, the lower pressure air forms a ‘blanket’ over the high pressure, causing cloudiness, lower temperatures, and winds from the east.
Tuesday, the damming effect wasn’t as pronounced, and ended just west of Gwinnett, so Atlanta wasn’t affected, and got warmer than it did further east. As the high moved further south, it got stronger, affecting a wider area today.
Meanwhile, we’ve got a summer report card. For the months of June - August, which in weather terms is the summer, temperatures were above average for the United States–the 22nd warmest year out of 114 years recorded, and also much wetter than usual–the 15th wettest out of 114 years.
States with extremely warm summers include California, New Jersey, Connecticut and Rhode Island. Georgia’s summer temperatures were also warmer than normal, ranking 31st warmest out of 114. However, much of the warmth was along the coast and the South Carolina border. The Atlanta area was closer to normal.
Tropical weather contributed to the wetter than normal summer. Mississippi, which felt the brunt of both Fay and Hanna had its wettest August ever. Florida and Alabama, both affected by Fay, had their second wettest August on record. Georgia had its 5th wettest August ever, and was near normal for the summer, again mostly due to the effects of Tropical Storm Fay.
Sphere: Related Content