Drought easing up

We have had the most active severe weather season in Alabama so far probably since 1998, and the large-scale flow indicates this may continue into April. While we don’t need any more severe weather, the bright side of all this is that all these weather systems coming through have really helped ease the drought over the past couple of months. The drought is not “gone”, but there are some very encouraging signs.

Looking at rainfall over the past 30 days, most of north-central Alabama has received 5-8″, with some spots near 10″. The map below shows the rainfall over the past 30 days as a percent of normal. Areas in green or blue have had above-normal rainfall, while the yellow areas have had below-normal rainfall.

(Courtesy SE River Forecast center)

The next graphic shows an animation of the drought-severity scale, with one image per week, since the beginning of the year (through Mar 4). The colors represent stage 0 through stage 4 drought. Notice how the area of stage 4 drought has shrunk this year, and much of BHM, which was in stage 4 drought for a long time, is now in only stage 2 or 3 drought.

(Courtesy U. S. drought monitor)

To see where the rainfall has made a big difference, we can take a look at some of the area lakes that were extremely low last year. Now, understandably, Alabama Power and the U.S. Army Corps of Engineers are holding some water back in the lakes, allowing them to fill up. But, without the rainfall, there would be no water to fill them up with! Check out the lake levels on Smith Lake (full pool 510 feet MSL), and Lake Martin (full pool 490 deet). Smith Lake was close to 20 feet below normal late in 2007.

(Courtesy Alabama Power)

Smith Lake has risen 15 feet this year, and is now at 507 ft., almost normal. Lake Martin has gone from near historic lows to near full summer pool in less than 3 months. Considering the area of Smith Lake, that rise represents roughly 97 billion gallons of water!

Bankhead Lake on the Warrior River, my favorite fishing lake, is controlled fairly closely, since barges navigate there. The levels have not changed a whole lot, but I checked the turbine release this morning at Bankhead Dam (Lock 17), and they were releasing 57,000 gallons of water per second.

Finally, take a look at high-resolution satellite satellite imagery of Lake Martin from Jan 1 and Mar 5. Notice how it looks like the lake is bigger and greener on March 5, perhaps representing some of the shallower sloughs that had been empty starting to fill up!

January 1

March 5

So, the lakes are filling up, the drought is easing, and if rain continues to be at or above normal, this summer should be much more pleasant than last summer, in many ways.

Category: Uncategorized