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Massive duststorm chokes eastern Australia; Atlanta floods ease

By: Dr. Jeff Masters, 2:22 PM GMT on September 23, 2009

A massive dust storm swept through eastern Australia today, turning the skies in Sydney a eerie shade of red-orange. The dust storm was reportedly the worst since the 1940s, and Sydney recorded its highest levels of particulate air pollution ever. The dust storm resulted from strong winds associated with a powerful low pressure system that swept through eastern Australia this morning. Winds today at the Sydney airport were sustained at 36 mph, gusting to 51 mph. Wind gusts as high as 64 mph were recorded in the Sydney area as the storm's strong cold front passed through. Particulate pollution levels are still in the hazardous range this evening in Sydney, but are expected to improve to the "good" range on Thursday as the winds die down and the dust storm dissipates.

Figure 1.. Strong northwesterly winds carry dust over Sydney, Australia, at 00 UTC 9/23/2009. Image credit: NASA.

Figure 2.. A strong cold front passing through eastern Australia this morning generated a sustained winds in excess of 20 mph over a large portion of the region.

Severe drought has affected large regions of Southeast Australia over the past three years (Figure 3). In isolated areas near Melbourne, the drought is the worst on record. The resulting loss of vegetation has created large regions of loose dust, which the strong winds from this week's storm was able to loft in the air and transport long distances.

Figure 3.. Rainfall deficiencies for Australia for the past three years. Image credit: Australian Bureau of Meteorology.

Atlanta floods ease
Very heavy rains exceeding fifteen inches soaked the Atlanta, Georgia region early this week, triggering widespread major flooding that continues today. Rainfall eased yesterday, and all of the rivers in the Atlanta area have crested and are now falling. Record flood levels were observed on at least seven rivers and creeks in the Atlanta area yesterday, breaking records that had been set as long ago as 1919. Utoy Creek near Atlanta broke its previous flood record by nearly 11 feet on Tuesday. The floods have killed at least nine people and did $250 million in damage. Portlight.org is experimenting with a new disaster relief strategy for this flood--they have decided to adopt a single family to help, the Baxter family of Lithia Springs, Georgia. The Baxters lost their home, car, furniture, clothes, and everything else in their house, and need assistance to defray the short-term expenses of lodging, food, and clothing, so help out if you can.

Figure 4. Radar estimated rainfall for the Atlanta, Georgia region ending on September 22. More than 15 inches (white colors) had fallen in and around Atlanta.

There are no threat areas in the Atlantic to discuss today, and none of our reliable computer models are forecasting tropical storm development over the next seven days.

Jeff Masters
Parkinson Avenue 06:15
Parkinson Avenue 06:15
Unusual sunrise 1


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