Re-visiting the summer storm of July 22, 2003 - "Hurricane Elvis"

Monday, July 22, 2013 marks the 10 year anniversary of the "Mid-South Summer Storm of 2003," or as it is now called in Bluff City lore - "Hurricane Elvis."  Like the Ice Storm of 1994 and Super Tuesday tornado that struck Hickory Hill, Hurricane Elvis is a weather event that is ingrained in the psyche of anyone who lived in the Memphis metro that summer.  In meteorological-speak, Hurricane Elvis was a "derecho" that formed from a mesoscale convective system.

A massive tree was uprooted on Belvedere Street. Photo credit Mike Maple, The Commericial Appeal.

What is a derecho?

A derecho is, in it's most basic form, a very long-lived severe wind event.  To be deemed a derecho, a severe wind event must meet stringent requirements set by Johns and Hirt (1987) and re-stated by McNeil, et al (2003) from NWS-Memphis in their report on the storm.  The requirements are:

1. A concentrated area of thunderstorm-induced wind reports or damage resulting from wind gusts of at least 58 mph over a path of 249 statute miles (400 km)
2. The reports in this area must exhibit a "non-random  pattern of occurrence" as a singular (serial) or multiple (progressive) swaths
3. Within the area, there must be at least 3 reports, separated by 40 statute miles (64 km), of F1 damage on the Fujita scale or gusts of 74 mph
4. No more than 3 hours may elapse between successive wind events

In other words, a line of thunderstorms with some damaging wind reports is NOT a derecho in and of itself.  In addition, a line of storms cannot be called a derecho until it has met ALL of the above criteria (which is not when it first forms, as some media outlets are known to do, but hours into the event).

The atmospheric setup

The environment across the Mid-South on that fateful Tuesday morning was primed to support severe thunderstorms, despite being at diurnal minimum (lowest heat content in the atmosphere, which is typically just after dawn).  At the surface, a weak stationary front was draped across the metro and had stalled, as fronts typically do in this part of the country in the summer.  Low-level moisture had pooled along and ahead of the front as surface dewpoints were in the mid 70s. The atmosphere over the metro was highly unstable for 6am (CAPE was 3400 J/kg per McNeil, et al).

Surface map at the time of the derecho showing a stationary front over the region (click for larger map)

Analysis of CAPE values at 09Z (4am CDT) indicating an extreme amount of instability for this time of day

Aloft, drier air was present in the mid levels of the atmosphere (a recipe for downbursts) and the Mid-South was positioned in a northwest flow regime. In northwest flow, winds aloft blow from northwest to southeast - a prime pattern for mesoscale convective systems (or large areas of thunderstorms) to affect the region as upper-level disturbances rode the northwest wind into the region.  An upper level trough was located to our north and northwest and the jet stream was to our north, positioning the Mid-South in a favorable environment for convection with diverging wind (a pattern in which the wind separates, or diverges, from a common point) over the area at jet stream level.  All of these were ingredients for severe weather that morning.

The mid levels of the atmosphere (500mb, or ~18,000') showing the northwest flow over the region

Jet stream level chart showing a jet streak (light blue) over the Ohio Valley and divergence over the Mid-South

Meanwhile, one of those pesky upper-level disturbances had induced thunderstorms over the Ozarks in the wee hours of Tuesday morning and they strengthened as they rode the northwest flow into the area and encountered a very unstable airmass.  As they did so, the storms, now a series of supercells with a history of producing damaging wind across northern AR, coalesced into a bow echo with strong inflow wind on the rear side of the line causing supercells to merge just across the river from Memphis.  When they merged, the inflow wind was aided by convective downbursts and hit the ground just before 7am with a force Memphians will never forget.

Radar reflectivity as the bow echo/derecho raced through Midtown, where much of the most significant damage occurred. Courtesy McNeil, et al (2003).

The storm began producing severe wind gusts over northern AR around 3am, peaked in the Memphis metro and along the TN/MS state line between 6-8am, then continued east into northwest AL and far southern middle TN from 9-10am.  Once it was all said and done, there was plenty of evidence to rate the storm not only a derecho, but likely one of the worst to ever hit Memphis.  The derecho's path length was 400 miles and it traveled this distance in a period of 7 hours - a forward speed of nearly 60 miles per hour!

Seven-hour path of the Mid-South Derecho, courtesy NWS-Memphis.

Courtesy NWS-Memphis - axis of heaviest wind damage highlighted

The immediate effects

The "Mid-South Summer Storm of 2003" caused extensive damage across the region (estimates were more than $500 million in 2003 dollars), but was concentrated in Shelby County. Other areas hit hard were northern Tunica County, DeSoto County, Fayette County, and points east along the TN/MS state line. The derecho brought torrential rain and extreme wind reports that topped out at 102 mph from a weather station at AutoZone Park and unofficially 108 mph from a barge on the Mississippi River.  Other gusts included 84 mph at WREG-TV on the riverbank south of downtown, 77 mph at the Agricenter, and 61 mph at Memphis International Airport.  One death was directly attributed to the storm (from a falling tree), while six others died in the aftermath from various related accidents, fires, and carbon monoxide poisoning.

Damage to the Gibson Guitar Factory and a leaning crane on the FedExForum construction project. Photo credit Jeremy Atherton.

In the storm's path, many trees were torn down causing the most damage by falling on houses and cars, in the streets, and most of all on power lines. More than 1.1 million cubic yards of tree debris was collected in the weeks following the storm. The wind and falling trees left more than 1,300 power poles damaged, caused 2,000 transformers to blow, and downed 76 miles of wire. At the end of the storm, some 750,000 people (~338,000 of Memphis Light Gas and Water's [MLGW] customers) had lost electricity in Shelby County alone, as 279 of their 435 circuits were knocked out. MLGW worked diligently, including doubling its workforce through contract workers, to re-build the electrical grid and restore power. Over 100,000 people were still without power after ten days and many residents had to wait as long as 16 days in the blistering summer heat to have their power restored.  The utility alone suffered $30 million in damage.

Linden Avenue looked like many other Midtown streets following the storm. Photo by Mike Maple, Commercial Appeal.

Also in Midtown, Scott McNeil of the NWS took this picture on Central Avenue.

The derecho caused 600 of the 800 traffic lights in Memphis to malfunction. Therefore resident's commutes to and from work took much longer. The powerful wind also caused a crane that was a part of the FedExForum construction project to bend, which resulted in Beale Street being shut down temporarily due to the hazardous conditions overhead. Some areas experienced flash flooding as well. For example, Idlewood Elementary had its entire cafeteria flood and ten classrooms were heavily damaged as part of its roof was blown off.  Memphis International Airport was closed for a time after the storm and President Bush declared a federal disaster area for Shelby County, clearing the way for federal assistance during the recovery effort.

In the suburbs, 80% of the Germantown area experienced power outages. Bartlett had 1,000 homes and businesses with damage. Lakeland had a total of 500 houses with damage. The Collierville area had 469 homes damaged.

Lingering effects

During the time after the storm, the crime rate rose significantly. Between July 22 and August 4, residential burglaries rose from 431 the year before to 514 in 2003. Business burglaries also rose from 113 to 218.  Because there was no power, many citizens resorted to using candles as an alternate source of light. Due to the use of candles, some fires broke out, one of which caused the death of a two month old baby.

Because it was summer in Memphis, many invested in a generator to power air conditioners and fans. Although this may have helped them cool off, carbon monoxide poisoning became a problem. In one case, ten people were found unconscious in their home and a toddler died.  Even though Memphians without power will remember sweltering conditions, records indicate that in the 16 days starting on July 22 (the period of time it took to restore all power), the average high was only 87 degrees and only 6 of those days saw a high of 90.  A couple of days did reach the mid 90s however, and overnight lows in the 70s much of that period contributed to the heat issue, as it didn't cool off enough at night to provide some even a few hours of relief on many nights.

Advance warning

The National Weather Service report (McNeil, et al) points out that, given radar systems in place at the time and the angle that the storm was coming into the county, the NWS was prevented from seeing the full magnitude of the wind velocity before the damage reports started rolling in.  However even with this limitation, a Severe Thunderstorm Warning was issued for Crittenden County at 6:15am and for Shelby County at 6:29am, about 12 minutes prior to the storm reaching downtown.  That warning, and a subsequent re-issuance, were in effect for Shelby County until 7:30am.  Warnings were also issued for counties downstream prior to the storm arriving.

A warning issued at 7:02am for DeSoto and Marshall County was the first to mention a "history of wind damage," though the magnitude of wind damage was not given.  At 7:16am, the Shelby County warning was re-issued with the wording "wind damage has been reported across Shelby County," but there was still no enhanced language indicating the extreme nature of the damage.  Three minutes later, a Fayette County warning indicated "widespread wind damage across Shelby County."  Obviously, the extent of the damage was arriving in the NWS office as the storm moved through Shelby County and efforts were made to increase the strength of the wording in subsequent warnings.

The warning process since 2003

From having personally read weather warnings and follow-up statements for the past decade, great advancements have been made in the warning process, including more use of enhanced language, regular use of severe weather statements that follow a warning with additional information on the threats posed, and certainly the 2007 transition to polygon warnings for specific areas independent of political boundaries.  In addition, new tools and radars are providing even more information and data to NWS warning forecasters.  However, there is still work to be done in this area.  We are currently in an era of modernizing the warning process even further, including the use of social scientists and surveys to determine what the best way is to get a strong message out to the public to minimize apathy and increase awareness.

A drawing created by Sher Stewart after the storm

MWN blog entries on other recent Memphis area derechos:

June 12, 2009 - Event analysis of Mid-South Derecho - June 12, 2009  and Follow-up to the June 12 Mid-South derecho
April 4, 2011 - Early April severe weather events foreshadow a busy season (Top 11 of '11, #6)
June 11, 2012 - Derecho sweeps through the Memphis metro on June 11

References:
McNeil, S.J., et al, 2003: The Mid South Derecho - 22 July 2003. (Also, PowerPoint in PDF format)
Johns, R. H. and W. D. Hirt, 1987: Derechos: widespread convectively induced windstorms. Weather Forecasting, 2, 32-49.
Storm Prediction Center (SPC) Derecho page
SPC Page on Mid-South Summer Storm of 2003
WMC-TV special, "Destruction at Dawn", August 2003.
Commercial Appeal 10th Anniversary Retrospective
Wikipedia - Memphis Summer Storm of 2003

Erik Proseus,
MWN Meteorologist

Abigail Topham,
MWN Student Intern

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Derecho sweeps through the Memphis metro on June 11

A mesoscale convective system (MCS)-turned-derecho swept through the Memphis metropolitan region on Monday afternoon, June 11.  Beginning as a cluster of storms in west-central Missouri, the system gained strength, feeding on very unstable air in it's path as it rounded an area of more stable air as it dove southeast into the Mid-South and then all the way to the Gulf Coast.

What is a derecho?

A derecho is a type of MCS that produces widespread severe and damaging straight-line wind.  They aren't as common as other types of MCS's and tend to feed on the warm and unstable airmasses produced during the summer months.  A derecho, by definition, must produce a swath of severe wind (58 mph or greater wind gusts) and damage over a path of at least 240 miles.  These systems last for hours and must have produced continuous damage with no breaks for more than a couple of hours.  Typically they appear as a large bow-shaped band of showers and storms.  The most cited example locally of a derecho is the "Mid-South Summer Storm of 2003," more commonly referred to simply as "Hurricane Elvis" which occurred during the morning rush hour on July 22, 2003.

June 11, 2012 Derecho

As seen in the radar animation of this particular storm system below, the derecho began over Missouri in the late morning hours.  It dropped southeast through the Mid-South around mid-afternoon, then elongated and continued unabated through the Deep South, affecting Mississippi and Alabama before falling apart as it moved over the Gulf of Mexico.  The total distance traveled was over 600 miles! As you can see, additional storms fired along the outflow of the derecho over southern Arkansas and eastern Oklahoma and Texas, which then became an MCS of it's own as it dove south over Louisiana in the wake of the derecho.

Radar animation of the long-lived derecho of 6/11/12. Courtesy UA-Huntsville.

Derecho Impacts

The impact of the derecho is clearly shown below in the graphic of severe wind reports from Monday and Monday night.  Over 300 reports of damage or measured wind of 58 mph or greater were recorded, though some were part of the additional MCS that formed over Louisiana and Texas or separate storms along the Atlantic coast.

Severe wind reports (308) from 7am Monday through 7am Tuesday as received by SPC.  

Locally, there were many reports of trees and power lines down, small outbuildings damaged or destroyed, and thousands without power in the storm's wake.  MLGW ended up with nearly 15,000 customers without power by Monday evening, though all but a couple of thousand had been restored by Tuesday morning.

Just one example of hundreds in the Memphis area - a tree down in north Bartlett

Though not producing twisting tornadic wind, wind speeds can rival weak tornadoes in these storms.  Thus, it is very important that precautions be taken during Severe Thunderstorm Warnings, at least staying indoors, away from windows, and out of harm's way.  The 60-80 mph wind that frequently accompany derechos can also topple, or severely damage, mobile homes.  If you live in one of these structures and have knowledge of an impending storm such as this one, it is always best to leave for sturdier shelter. For additional severe weather safety tips, visit the MWN Storm Center.

What was your experience from this derecho? Did you lose power and if so, for how long? Did you lose any trees or have other damage?

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Still frames of a nearby lightning strike

These still photos were part of a short video taken with my digital camera as the June 12th summer storms (derecho) approached the northeastern Memphis suburb of Bartlett. I happened to get a very close lightning strike just before I shut the camera off and extracted these individual frames from it. The time elapsed from the first to the last picture above was about half a second. You can click on each picture for a slightly larger version. Of course, we all know the result of that storm in the Memphis area.

Also, I'd like to say thanks again to my loyal readers and blog followers. My blog passed 15,000 direct visitors since July 23, 2008 - just 3 days shy of one year. Many more of you follow the blog on Facebook and other sources - THANK YOU!!

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July 22, 2009 - the 6th anniversary of "Hurricane Elvis"

Today marks the 6th anniversary of the infamous "Hurricane Elvis" storm which swept across the metro Memphis area on July 22, 2003 at about 7am CDT. The aftermath of that derecho, with its 100-mph wind, was incredible as more than 750,000 people lost power (some for more than 3 weeks), structural and infrastructure damage was widespread (75% of the traffic signals were out and the airport closed), and seven people lost their lives.

Though the Memphis area has seen a couple of other strong derechos since that storm (most recently "Little Elvis" on June 12, 2009), I am hopeful that we never have to experience another system of this magnitude.

Here are some links on Hurricane Elvis:

• Wikipedia's page on the summer storm of 2003


• A write-up by the Storm Prediction Center on the event


• NWS-Memphis analysis of the event (PDF)


• Memphis/Shelby County EMA's photo gallery

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Follow-up to the June 12 Mid-South derecho

Clean-up is ongoing in the Memphis area after "Hurricane Elvis: The Sequel," as some call it, came roaring through late in the afternoon of June 12. It's been 3 weeks since the derecho struck - complete power restoration by MLG&W took a few hours over 1 week to retore the approximately 140,000 customers that lost power during the storm and in a subsequent storm roughly 36 hours later.

My area of town (Bartlett) still has at least a few more weeks of debris removal (mainly trees) to go with the hardest hit area stretching east near Elmore Road from west of Bartlett Boulevard to Kirby-Whitten Road. In fact, city officials have estimated that more debris was created from this storm than the original "Hurricane Elvis" of July 22, 2003, which tended to focus its damage over the heart of Memphis rather than in its northern suburbs. Below you will find the process Bartlett is using to rid themselves of the debris - huge piles of dead trees limbs, branches, and trunks are being ground up into mulch. Be looking for a mulch giveaway at some point!

If you haven't read my event analysis of the storm, it's worth checking out (in my humble opinion) and is written for the layman to understand. There are also links to my damage photos, radar and satellite imagery, etc. at that link as well.

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Weather wrap-up for Thursday, June 25

The heat continues across the Mid-South, though a few degrees cooler than earlier this week and also less humidity, therefore Heat Advisories have not been issued since the "cool front" passed through Tuesday night. We may see them return though for Saturday as heat index values will once again climb near 105 or higher. Another front looks like it will be coming through Sunday night, so that may end the string of 95+ degree days and drop the humidity levels once again. For Friday, ozone levels have crept up in the city and will be high enough tomorrow to cause problems for those with certain respiratory problems. Thus, a Code Orange Ozone Alert has been issued and an Ozone Action Day declared. Take precautions in this heat.

Today marks the 9th day of 95 degree heat, with at least two more coming (maybe Sunday too). The rain chances with Sunday's front will be low and a very weak front will get close enough tomorrow to perhaps spark an isolated cell or two late in the afternoon or evening Friday. Maybe someone will get lucky and get a few drops!

Speaking of heat, it's hot, but not necessarily record-breaking, until yesterday morning when the old maximum low temperature of 80 degrees was eclipsed by a balmy 81 degree low! The old record stood for nearly 80 years. Record highs are running in the lower 100s so I don't think we'll see any high temp records broken in this current streak.

In other news, I have added some additional damage photos from the Elmore Park area of Bartlett to the album of pictures I took of the damage from the Mid-South derecho on June 12. If you haven't read my event analysis or checked out the radar and satellite loops, home video of the storm as it passed through, and damage photos, I encourage you to do so. You can find the information by clicking here.

Finally, NASA is set to launch the newest weather satellite into orbit tomorrow (June 26). GOES-O will lift off aboard a Delta IV rocket if the weather holds up. (How about that for ironic? A weather satellite is delayed going into space due to the weather??) GOES-O will live in storage mode among its siblings, GOES-10, -11, -12, and -13, in an orbit 22,300 miles above the Earth. It will be called into service should there be a failure of one of the other operational satellites. For more information on GOES-O, see these links:
http://cli.gs/X7sRNM (NASA)
http://cli.gs/v9nrMu (NOAA)

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Event analysis of Mid-South Derecho - June 12, 2009

I have put together, and posted on MemphisWeather.net, an event analysis of the mesoscale convective system/derecho that blasted through Memphis and many parts of the Mid-South on Friday afternoon, June 12, 2009. There are many damage photos, links to radar and satellite loops, storm reports, and commentary on the event. I also have several photos of the spectacular sunset that occurred that evening, after passage of the storm system. Check it out, download the PDF if you wish, and feel free to pass the link on to others who might be interested and comment on the report here if you'd like. I'm interested in your feedback! The PDF report can be found here.

Brief recap of 6/12/09 Memphis derecho

My comments here will be brief as a full-length commentary with pics is in the works. A major convective system (derecho) passed overhead the WXLIVE! sensors of MemphisWeather.net at 5pm, lasting about 20-25 minutes. Tornado sirens were activated and my family headed for the interior closet during the peak of the storm. The NWS confirmed a 150 yard path length EF-1 tornado touched down in Bartlett very near where my parents live (within a mile). Trees, tree limbs, flagpoles, some street signs and traffic signals, and even a couple of buildings were damaged or destroyed by the wind. 139,000 people were without power at it's peak on the Memphis Light, Gas & Water network (greater Memphis). (See link to the right for the current outage map or click here.)

I wish to apologize profusely for the abrupt loss of severe weather alerts (and many other features of MemphisWeather.net) during the height of the storm. The computer equipment that produces the information and alert e-mail suffered a major power and internet connectivity loss at 5pm as the storm passed. The outage lasted 19 hours, with internet down an additional 3.5 hours. All service is now restored. While the data loss is regrettable, there was simply nothing that could be done given the current resources available.

Derecho moving through Ozarks and effects on Memphis weather

A very strong convective system called a derecho (learn more) is moving rapidly east-southeast this morning through the Ozarks. Wind gusts of over 80 mph have occurred with this system and tornado warnings are posted for many locations as it moves through. A movie loop of Springfield, MO radar from 8:00-8:45am is shown above. Memphis is in the lower right corner of the map.

This is the same type of system that came through Memphis on July 22, 2003 and became known as"Hurricane Elvis." It will continue moving rapidly east-southeast towards the Mid-South as the morning progresses. Another convective system moved through middle TN earlier this morning and put down an outflow boundary across portions of west TN as well. With a cold front seeping into the area from the north, the groundwork is being laid for scattered thunderstorms beginning around the lunch hour and throughout the afternoon. Whether the derecho comes through this area, especially in it's current form, is in doubt, but the threat exists. In fact, a Tornado Watch has just been posted for most of west TN, except the counties bordering MS, including Tipton County. Stay with MemphisWeather.net and interactive StormView Radar as this weather system approaches. Updates will also be posted as necessary on my Twitter feed.