Pick Your Poison: Drought or Flood?

WATCH VIDEO: 2010 Hurricane Season in 1 Minute

August 19, 2011 -- We can all get a little wacky when we’re under pressure. Apparently, weather is similarly vulnerable. In recent months, persistent ridges of high pressure have been driving storms away from the south central United States, leaving that region parched while drenching others with unusually heavy rain. The effects of this weather dichotomy are clearly visible in satellite imagery released this week at the NASA Earth Observatory.

The wacky mix of wet and dry weather left its mark in some unusual plant growth during the month of July (above). Here’s what the colors mean:

*BEIGE: Plant growth was about average for the month of July.

*GREEN: Plants grew more than average in areas clearly coinciding with the heavy downpours that swept the Northern Plains and Western states.

*BROWN: Plants grew poorly, due to worsening drought across Texas, Oklahoma, New Mexico and several other states.

BLOG: Forty-one percent of U.S. abnormally dry

As extreme as the drought has been, it is not enough to offset the heavy rains that exacerbated flooding along the Missouri River, also revealed in NASA imagery released this week. The muddy Missouri gets its start in Montana and crosses both Dakotas—all within the region of unusually heavy rain—before turning south. In the Midwest this river forms the border between Nebraska and Iowa, which remained flooded in early August.

One place the Missouri River floods lingered was between Nebraska City and Hamburg, Iowa, which the Landsat 5 satellite captured in natural color August 10, 2011 (above). The inundated fields and floodplains east and west of the river are easier to make out when compared with an image of the same area taken about a year earlier, on August 23, 2010 (below), which shows the river under normal circumstances.

What will it take to end the devastating dichotomy? Hurricanes may help with drought. NOAA’s Climate Prediction Center says it is now 85 percent confident that the country faces an above-average hurricane season.

BIG PIC: Hurricane Dora Off Pacific Coast of Mexico

“The atmosphere and Atlantic Ocean are primed for high hurricane activity during August through October,” said Gerry Bell, NOAA’s lead seasonal hurricane forecaster said in a recent report. “Storms through October will form more frequently and become more intense than we’ve seen so far this season.”

Here's a conundrum: NOAA forecasters say it would take 20 inches of rain by the end of October to end the drought in many southern states. Hurricanes could deliver, but then what about the flooding?

by Sarah Simpson

IMAGE 3: Missouri River basin between Nebraska City and Hamburg, IA, on August 23, 2010. (NASA Earth Observatory)