The Top 11 of '11: Mid-South weather stories from MWN (part 5)

Here we go!  The top 2 Mid-South weather stories of 2011 are revealed below.  To read about the other 9, follow the links below:

• Part 1 (#11 Aurora Borealis appears in Mid-South skies, #10 MWN at the forefront of social media nowcasting, #9 Addition of key team members helps MWN expand it's presence)
• Part 2 (#8 Dual early-season accumulating snow events, #7 MemphisWeather.net debuts mobile apps, then raises the bar with StormWatch+)
• Part 3 (#6 Early April severe weather events foreshadow a busy season, #5 Severe weather season ends with one last round of storms in late May)
• Part 4 (#4 January-February snowstorms contribute to the snowiest winter in 25 years, #3 "The Summer of '11" - third hottest Memphis summer in recorded history)

#2. Effects of the April 25-28 Super Outbreak on the Mid-South
It has gone down in the history books as the super outbreak to rival the original of 1974.  In fact, many of the stats indicate that it has surpassed the Super Outbreak of 1974 in many respects. The month of April was the most active tornado month in U.S. history and the 4-day period from April 25-28 saw over 200 tornadoes produced in 5 southeastern U.S. states, killing 316 and injuring more than 2,400.  15 of the tornadoes were rated violent (EF-4 or 5).  Total damage is estimated at $4.2 billion from storms on this day alone (all statistics from "The Historic Tornadoes of 2011," a NOAA Service Assessment).

Memphis area severe weather reports from April 25-27, 2011

The nearest significant damage from this outbreak was not the highly-publicized Alabama tornadoes, but a monster EF-5 that nearly wiped Smithville, MS (130 miles southeast of Memphis) off the map.  It was the first EF-5 recorded in the U.S. in three years and occurred almost simultaneously with another EF-5 about 100 miles south near Philadelphia, MS. Maximum wind was estimated at 205 mph along the 37-mile path of the twister.  In all, 17 people lost their lives and 40 more were injured.  A recap of the event, authored by WTVA meteorologist Jennifer Watson and MWN meteorologist Erik Proseus, appears on the MWN Blog and a video tribute can be found here.  Below are photos taken in Smithville three months after the storm by Erik.

Indeed, even though there were dozens of severe weather reports in the metro over the 3 day period (see image above), the Memphis area was actually spared from what could have been utter chaos similar to what was seen in places like Smithville, MS, Tuscaloosa/Birmingham, AL, and many other places in the southeast.  The greatest effect on Mid-Southerners from this outbreak though, in our opinion, was not from property damage, but on our psyche.  The extended period of destructive weather was well-forecast, beginning nearly a week ahead of time, and it received a lot of airtime (and a lot of hype) leading up to, through, and after the events that occurred.  The Memphis area was under a moderate risk of severe weather for two days, upgraded to a high risk on one of those, and then a slight risk on the day that all hell broke loose in MS and AL.  Multiple waves of severe storms, all capable of producing damage and potentially loss of life, passed through the region and at times it seemed the tornado sirens would never stop sounding.

All of this affected the psyche of the general public in different ways.  Some grew weary and began ignoring the warnings, which led to a complacency that is far more dangerous than the Weather Service missing a tornado warning.  Others grew fearful and became paralyzed, which leads to indecision during critical times.  Both of these have the opposite effect of what SHOULD be the public's reaction to severe warnings, which is to take action.  Part of MWN's mission is to ensure that the public is properly informed and prepared in case of severe weather; another part is to make sure that the public knows when to exercise their safety plan.  Through our severe weather nowcasting on social media, we hope to accomplish both of these. Our stats for the months of April and May indicate that we are doing a good job in both regards.  However, if we can reach more people, our hope is that the sense of complacency is replaced by preparedness on a broader scale. If it saves one life, it is well worth the effort.

#1. Mississippi River rises to within inches of an all-time record at Memphis
We now come to the #1 event in our countdown of the Top 11 of ’11 and without a doubt it’s an event Memphians and Mid-Southerners are sure to remember for years to come. With a long, snowy winter for much of the country in the rearview mirror, the warmth of spring began the annual melt of the deep snowpack in the northern states, sending large amounts of water into area rivers and tributaries. All of this water would begin flowing downstream into the Mississippi River by April. Meanwhile, multiple excessive rain events during the spring across the Ohio Valley (300% of normal) and Mid-South led to even more water pouring into the Mississippi River watershed. This combination of events led to a “perfect storm” of sorts, setting the table for an historic flooding event for the area.

While flash flooding and tributary flooding of rivers like the Wolf and Loosahatchie were a significant problem early on, especially in areas of northern and eastern Shelby County, the impacts from flooding on the Mississippi became much more severe and widespread. Record or near-record crests were forecast at multiple points, including Memphis. Making matters worse, backwater flooding from the Mississippi into the area tributaries would keep those water levels high as well, putting even more people at risk. As the waters began rising and homes and businesses became threatened, people evacuated to higher ground, waiting to see how high the river would go. That day came on May 10, and with much of the national media in Memphis, the river crested at 48.03 feet, just inches short of the all-time record of 48.7 feet during the Great Flood of 1937.  Pictures taken by MWN meteorologist Erik Proseus are contained in the photostream below.

In the days following, the waters would slowly recede, allowing people to return home and begin the cleanup process. Slowly but surely, affected businesses reopened, including the Tunica casinos which had been closed for weeks.  While the floods were devastating for many, they also brought people in our area together. Whether it was to donate to those affected or fill sandbags to keep the high waters at bay, it presented a classic example of the community spirit we often see in the area. Though the Great Flood of 2011 is now a memory, it’s an event that will be well-recorded in the history books and a memory that will remain with many of us for the rest of our lives.  For NOAA's perspective on this billion-dollar weather disaster, watch the video below.

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Thanks for following along on this five-part blog series.  It's definitely been an amazing weather year in the Mid-South and across the nation.  In fact, the U.S. experienced a record ELEVEN billion-dollar weather disasters in 2011.  Let's hope that 2012 is a quieter year weather-wise!  I also want to thank MWN intern Kevin Terry for contributing to this series, as well as his dedication as a blog and social media poster for MWN!  Kevin is signed on with MWN through the first half of 2012 and will continue with his regular duties through that time.

Follow along with MemphisWeather.net on Facebook and Twitter throughout 2012 for the latest weather conditions, forecasts, stats, and nowcasts.

The Top 11 of '11: Mid-South weather stories from MWN (part 4)

For the past 3 days, we've been counting down the Top 11 Mid-South weather stories of 2011. Today continues the countdown as we approach the top two events on Saturday. First, we unveil numbers 3-4. To catch you up, if you missed the first 7, here are the links:

• Part 1 (#11 Aurora Borealis appears in Mid-South skies, #10 MWN at the forefront of social media nowcasting, #9 Addition of key team members helps MWN expand it's presence)
• Part 2 (#8 Dual early-season accumulating snow events, #7 MemphisWeather.net debuts mobile apps, then raises the bar with StormWatch+)
• Part 3 (#6 Early April severe weather events foreshadow a busy season, #5 Severe weather season ends with one last round of storms in late May)

# 4. January-February snowstorms contribute to the snowiest winter in 25 years
For the third straight winter, snowfall was prevalent in 2010-2011.  Most of that snow fell in 5 events during January-February 2011. For the most part, each of the events were well-forecast and dropped "significant" snow (for the South) somewhere in the metropolitan area.  A brief recap of each event follows.

January 9-10 snowfall totals

January 9-10: The preferred storm track for accumulating snow materialized early in the month as low pressure moved along the Gulf Coast and an upper-level low traversed central MS. Snowfall totals were highest just north of the low as 6-10" fell over north MS.  The immediate metro area received 3-4", while areas north of the metro picked up1-2". The graphic at left summarizes the totals (click for larger image).  A Winter Storm Warning was issued ahead of the storm and the official total for Memphis was 3.0".

January 20 snowfall totals

January 20: Ten days later, another upper-level low, this one trailing a cold front, caused rain to change to snow during the afternoon hours, which continued into the evening. Snowfall totals ranged from 1" north of the city to 3" to the south.  Memphis International recorded 2.0" for this event.  Snowfall totals are shown in the graphic at right.

Snow cover visible on satellite Jan. 26

January 25: A very similar setup to January 9 occurred again on the 25th, only with lesser amounts of moisture, thus lower snowfall amounts.  Rain changed to snow in the late afternoon and continued through the evening, dropping 1.1" at the airport with higher amounts to the east and north.  Snow mainly fell over west TN with this event.


February 7: While most were people were looking ahead to a much larger event due in on the 9th, a quick-hitting system dropped amounts ranging from 0.2" at Memphis Int'l to 1.8" at MWN in Bartlett.

February 9 snowfall totals

February 9: This well-publicized and well-forecast event once again followed the preferred storm track as low pressure rode the Gulf Coast, pumping moisture into the Mid-South where cold air resided.  Highest snowfall amounts were again found over north MS and east-central AR where 3-6" amounts were common.  Lowest amounts were found over northeast AR and northwest TN.  In the metro, amounts were consistently in the 2-4" range, including 3.1" at Memphis.


By the end of the the winter, Memphis Int'l had recorded 9.7" of snow for the season, 6.1" over the normal of 3.1" and the most since the winter of 1987-88.  In addition, there were 6 days with measurable snowfall, the most since 1984-85.  Mid-South snowfall totals for the winter are shown in the graphic below.

Winter 2010-2011 snowfall amounts for the Mid-South

# 3. "The Summer of '11" - third hottest Memphis summer in recorded history

Many Mid-Southerners like to complain about the heat and humidity of the summer.  Many are transplanted northerners, others tolerate it for different reasons.  And while an average Memphis summer can be "sho'nuff" hot and humid, the summer of 2011 left even the most tolerant of us begging for 24x7 A/C - and for good reason.  By the first week in September, the National Weather Service had officially placed the summer of '11 in the record books as the third hottest behind the previous year (2010) and the benchmark for Memphis summers - 1980.  In fact, three of the past five summers, including 2007, are ranked in the top 5 hottest of all time (records go back to the 1880s).

The average temperature for this summer (meteorologically, June-July-August) was 84.6 degrees, which was 1.0 degree off the record summer of '80.  Several daily records were broken, including the record high of 106 on August 3, which fell 2 degrees shy of the all-time heat record set on July 13 in the storied year of 1980.  A few other sweltering stats about this summer: 10 daily heat records were set or tied; the average high and low in July was 95 and 77, respectively; and only 10 days during the three-month period failed to reach at least 90 for a high (five of those in mid-August). The heat started early with three records of 99 set in the first week of June and the June-July period tied 1980 for the hottest ever at 84.9 degrees.  For more details on each month's climate data, click these links:  June  July  August  Besides the heat, humidity levels were also abnormally high, even by Memphis standards, for long stretches this summer.  Heat indices soared above 110 and overnight lows failed to drop below 80 on several occasions, prompting Excessive Heat Warnings for the area.  With two summers in a row making the top 3, we're due for a cooler summer in 2012!

This leaves only the top 2 stories remaining!  What events topped one of the snowiest winters in recent memory and the third hottest summer ever?  Find out tomorrow as we conclude the "Top 11 of '11!"