Year in Review - 2011

The most persistent hydrologic feature for Central Alabama throughout 2011 was the drought that affected much of the area, especially areas to the south and east of the Interstate 20 corridor. 

As the year began, Moderate (D1) to Extreme (D3) Drought prevailed across the eastern and southern sections of Central Alabama and this general pattern continued into March.  However, late winter and spring rainfall brought some slight easing of the drought conditions in April and May, but by the first of June drought conditions were intensifying again in the southeastern sections as a drier weather pattern returned to the area.  By the middle of June, Extreme (D3) to Exceptional (D4) Drought had developed in the extreme southeast sections of Central Alabama, and these conditions persisted into the middle of July.  However, summertime thunderstorms in July gradually eased these drought conditions during the second half of the month. 

As often occurs, however, August brought a return of hot and dry conditions across Central Alabama with drought increasing once again, especially in the east-central and southeastern counties.  Tropical Storm Lee brought some much needed rainfall in September, but the greatest totals from this storm occurred in areas to the north and west of the most severe drought. 

During the remainder of the year, periodic rainfall occurred but as is typical for a La Nina weather pattern, the heavier amounts in general fell over the north and west sections of Central Alabama.  As a result, varying degrees of Moderate (D1) to Extreme (D3) Drought persisted through the second half of 2011, especially in the east-central and southeast counties. 

The major impacts from the Drought of 2011 were to farm crops. Many crop yields were diminished, with impacts also felt to some degree by cattle farmers as forage and hay yields were affected.  However, no major impacts to municipal water supplies and area reservoirs have occurred to this time despite low stream flows prevailing for much of the year.  Despite this, there have been some voluntary water restrictions in place in some areas since late spring and summer, with isolated mandatory restrictions declared in some of the southeastern counties.

A few heavy rain events developed during the normally wet springtime. On March 5th, Central Alabama received a widespread 1 to 3 inch rainfall. This rain event produced no flooding but may have been partially responsible for flooding later. On March 9th, a more substantial rainfall occurred where 2 to 6 inches fell areawide. Numerous reports of flash flooding were received. 

The summer months brought typical, mainly diurnal thunderstorm activity, with little in the way of widespread rainfall to produce river flooding.  The main problems encountered in June and July were from localized flooding of typical low-lying, flood-prone areas due to summertime downpours.  One of the more significant flash flood events occurred during the morning of July 20^th, when 3 to 5 inches of rain fell in and near the Alexander City area in Tallapoosa County.  This flooded a nursing home in Alexander City with numerous people having to be evacuated by boat.  One week later on the 27^th, 4 to 6 inches of rain in Southern Lowndes County also produced some localized flash flooding in that area. 

September typically brings a peak in tropical cyclone activity, and 2011 was no exception.  Tropical Storm Lee brought widespread heavy rainfall during the Labor Day weekend, especially over the north and west sections of Central Alabama. Storm totals of five to ten inches with locally higher amounts were measured along and to the north of the Interstate 20 corridor.  The southeast sections of Central Alabama generally received five inches or less.  Despite this heavy rainfall, antecedent conditions were very dry due to the ongoing drought, with most stream flows running well below normal.  As a result, only minor river flooding occurred and was limited to mainly the Black Warrior River.  The bigger problem was localized flash flooding.  Some of the most severe flash flooding occurred in the Birmingham metropolitan area during the afternoon and evening of the 5^th, when numerous roads and streets, as well as some 30 to 40 homes, were flooded in areas along Valley Creek and Village Creek.  Village Creek at Avenue W in Ensley crested at 14.57 feet, just below its record stage of 14.80 feet set in 1983. 

Although periodic and localized heavy rainfall occurred during the remaining months of 2011, no additional significant flooding was observed or reported.

Data supplied by the NWS BMX. Additional Flood Information can be found at the following links;

• Tropical Storm Lee in Central Alabama
• Alabama Daily Rainfall Plots
• Current Central Alabama Streamflows

Preliminary severe weather numbers for Central Alabama in 2011:

Data supplied by the NWS BMX. Additional information on severe weather and storm surveys can be found at the following links; 

• April 27th Super Outbreak
• April 15th Tornado Outbreak
• Severe Storms in Late March
• Additional 2011 Storm Surveys
• Alabama Storm Data
• Alabama Tornado Database

Tropical Cyclone Activity in the Atlantic Basin was well above average during the 2011 season. A total of 19 named storms formed, of which 7 became hurricanes, including 3 major hurricanes. The long term averages are 11 named storms, 6 hurricanes and 2 major hurricanes. There was also one tropical depression that did not reach tropical storm strength and was therefore unnamed. This high level of activity continues the active trend that started back in 1995. The 19 tropical storms represented the 3^rd highest total of all time. This number tied the output of 1887, 1995 and 2010.  However, the number of major hurricanes and hurricanes was only slightly above average.

Irene was the lone hurricane to impact the United States in 2011 and the first since Ike hit the Southeast Texas coast back in 2008. Irene was the most impactful tropical cyclone to hit the northeast coast since Hurricane Bob back in 1991.

A tropical depression developed in the Gulf of Mexico on Thursday, September 1 and strengthened as it remained nearly stationary becoming Tropical Storm Lee Friday afternoon, September 2. Tropical Storm Lee slowly moved northward toward the central Louisiana coast, eventually making landfall Sunday, September 4 near Vermillion Bay, LA, with maximum sustained wind speeds of 45 mph. Rain bands spread northward into Central Alabama Saturday afternoon, September 3, skirting the southwest corner of the area for approximately 6 hours before pushing further north across west Central Alabama. Moderate to heavy rainfall finally moved into other portions of the area overnight and continued through Sunday, September 4. Lee was downgraded to an extra-tropical cyclone early Monday morning, September 5. As the remnants of Lee interacted with an approaching cold front, heavy rainfall and gusty winds continued to affect Central Alabama through late Monday evening, September 7.

The remnants of Tropical Storm Lee brought beneficial rainfall to Central Alabama over several days. However, an extended period of heavy rainfall led to significant flash flooding across portions of north Central Alabama, including the Birmingham metro area. First Responders across the Birmingham area conducted at least 30 water rescues as heavy rainfall caused widespread urban flooding and area creeks to rise out their banks, flooding nearby streets and neighborhoods. In addition, two tornadoes touched down and strong gradient winds caused widespread damage across many counties.

Data provided by the NWS BMX and NHC.

National Hurricane Center 2011 Atlantic Hurricane Seasonal Summary

2011 Hurricane Season Movie:

On the morning of Sunday, January 9th, a low pressure system formed in the Gulf of Mexico just off the Texas coast. This low pressure system traveled parallel to the Gulf Coast throughout the day on Sunday and into the day on Monday before moving over the Florida panhandle and off the Atlantic seaboard Monday night.  By daybreak Monday morning, areas north of Interstate 20 were reporting anywhere from 1 to 14 inches of snow with the heaviest totals near the Alabama-Tennessee state line. Ice reports were as high as 0.50 inches in multiple counties south of Interstate 20.

During the overnight hours of Tuesday, February 8th, a low pressure system formed just off the Texas coast in the Gulf of Mexico. This surface low tracked eastward along the coast during the morning of Wednesday, February 9th, dragging moisture northward from the Gulf of Mexico and pulling cold air in from the north. After dumping upwards of 12 to 14 inches of snow in Arkansas, the combination of the two brought snowfall to much of central Alabama. The first report of snow was in Hamilton in Marion County beginning around 4 pm. As the precipitation moved through the state, many areas started out as light rain due to temperatures warming to around 50 degrees during the afternoon, especially across the southern counties of central Alabama, but the cold air was not far behind. Snowfall totals ranged from 4 inches in Lamar county to Trace amounts along the Interstate 85 corridor.

Snowfalls also occurred on Nov 29th and Dec 7th as two cold core lows passed just north of the state.  About one quarter of an inch fell in Marion county on Nov 29th and even less fell there on Dec 7th.

Data provided by the NWS BMX and NCDC.