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Free Copy: TR 93-04, The Summer of 1993:
Flooding in the Midwest and Drought in the Southeast (PDF File)
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by Neal Lott, Physical Scientist
September 1993
During the past summer, the Upper Midwest has been devastated
by severe flooding, while parts of the Southeast have been hit by
a heat wave and drought. The summary below gives an overview of
the details gathered thus far about these events. This summary
includes information provided by the National Climatic Data
Center, the Climate Analysis Center, the National Weather
Service, the Midwestern Climate Center, and various new media
reports.
1) The stage was set for severe flooding when the upper drainage
basin of the Mississippi River experienced a wet fall in 1992
followed by heavy winter snowfall and the ensuing spring
snowmelt. (Iowa reported its greatest snowpack since after the
winter of 1978-79.) Severe flooding began in May on the Redwood
River in Minnesota, and then in June on the Black River in
Wisconsin. Then came the record flooding of the Mississippi,
Missouri, and Kansas Rivers. The most severe flooding was
concentrated along a 500-mile stretch of the Mississippi River
between Cairo, IL and Minneapolis, MN; and along a 400-mile
length of the Missouri River from Omaha, NE to St. Louis, MO.
Some sections of the Mississippi River were above flood stage
from late March through most of August. Also, some areas were
flooded which were outside of the 100-year flood plain charts
(for previous flooding).
2) The Missouri River crested in St. Charles, MO at 39.3 feet,
and in Kansas City at 48.8 feet--17.5 feet above flood stage.
The Mississippi River at St. Louis crested at 49.6 feet--19.6
feet above flood stage. The old record for the Missouri River at
Kansas City was 46.2 feet in 1951. The old record for the
Mississippi River at St. Louis was 43.2 feet in 1973. Also, the
Kansas River at Kansas City crested at 54.9 feet--22 feet above
flood stage, and 3.9 feet above the old record.
3) Des Moines, IA residents were without water for 12 days due
to flooding of their water supply facilities. This is the
largest U.S. city (250,000 population) to go without water for
such an extended period. The Raccoon River in Des Moines crested
at 7 feet over its previous all-time record crest. Some
estimates indicated this to be a 500-year flood event for the Des
Moines area. Also, 85,000 people were without water in St.
Joseph, MO; along with 77,000 people in Alton, IL.
4) Due to flooding of many of the major roadways and
interstates, 'commuting' distances grew from several miles to
over 200 miles in some instances. Many of the bridges crossing
the Mississippi were destroyed or damaged by the flooding. From
July 16-20, there were no bridge crossings over a 212-mile span
between Burlington, IA and St. Louis, MO. Also, there was no MS
River traffic over a 585-mile span from Cairo, IL to St. Paul, MN
from late June through early August, resulting in over 5000
loaded barges being halted, and an estimated $3 million per day
in lost revenue. Similarly, the Missouri River was closed from
late June through early August over a 535-mile span stretching
from its confluence with the Mississippi River to near Sioux
City, IA. Eleven commercial airports were closed at one time or
another due to the flooding. Also, railway traffic was
devastated, with over 4000 miles of track either flooded or
idled, and over $200 million in estimated losses so far.
5) Well over 17 million acres were flooded, covering parts of 9
states. More than 22,000 homes were damaged or destroyed, and
over 85,000 residents had to evacuate their homes. More than 75
small towns near the rivers were completely flooded. Some of the
flooding occurred as levees collapsed after being weakened by
constant pressure from rising water levels. However, some
levees, such as the 52-foot 'wall' protecting St. Louis, held
back the rising waters. It is interesting to note that the St.
Louis levee was built to a level 9 feet higher than the previous
record crest for the Mississippi River, but less than 3 feet
higher than the 49.6-foot crest recorded on August 1. Over 6500
National Guard members were called in to assist in levee work. A
recent report on the various levees on the Mississippi and
Missouri Rivers indicates the following:
Federal levees (mostly Army Corps of Engineers)--20 of 275
have been overtopped or breached.
Non-federal and private levees--767 of 1091 have been
overtopped or breached.
6) Over 16,000 square miles of farmland were flooded, and crop
losses are expected to exceed $5 billion. Many farm animals,
such as cattle, have perished in the rising waters. Total crop
losses due to flooding or saturated fields now exceed 35 million
acres. The national soybean yield is now forecast to be 13
percent below last year's level, while the national corn yield is
expected to be down by 22 percent. Soybean prices moved to 4-
year highs on July 10 due to the damage assessments.
7) Overall damage estimates at this point are quite preliminary,
but already exceed $12 billion. Also, the 'economic' costs of
lost business revenue will have to be factored in at some point.
Local power plants were damaged in many cities, with electrical
service lost as a result (including 45,000 people without power
in Des Moines). Business districts were flooded in Davenport,
Dubuque, Burlington, and many other smaller towns. The overall
death toll from the flooding now stands at 48. Many church
groups across the nation have responded by sending money, food,
supplies, and personnel assistance to flooded areas.
8) The Missouri River, normally no more than a half-mile wide,
expanded to 5-6 miles wide north of St. Joseph, MO, and 8-10
miles wide east of Kansas City. Just north of St. Louis, it
reached 20 miles wide near its confluence with the Mississippi,
as the merging of the 2 rivers occurred 20 miles north of their
normal point of confluence. As a result, almost half of the 620
square miles of St. Charles County, MO were underwater. Also,
the Red River in North Dakota reached a level of 32 feet--21 feet
above flood stage.
9) 404 counties in the Midwest have been declared federal
disaster areas (all of IA, 62% of MO, 58% of WI and ND, 52% of
SD, 46% of NE, 40% of MN, 25% of IL, and 22% of KS). In
Alexandria, MO, flood waters reached depths of 8-10 feet, while
Kansas City residents found water 7 feet deep in places. In Eden
Prairie, Wisconsin, many people were stranded in floating cars
(including police officers), and manhole covers were 'blown' into
the air by the water pressure. Near Bismarck, ND, a severe
thunderstorm with very large hail stranded 3 girls in the
Missouri River--all 3 were injured by the hail but survived the
ordeal. In Iowa, measurable rainfall fell somewhere in the state
for 33 consecutive days from June 22nd to July 25th, and the
state has endured 10 consecutive months (through August) of above
normal rainfall. There have even been reports of snakes floating
along on top of propane tanks set adrift by the rising waters.
10) The waters in some areas remained above flood stage for many
weeks, and receded rather slowly. Many locations experienced not
one, but two record crests during the flooding. Continuation of
heavy rainfall in some areas during August further delayed the
river levels' fall. However, the Mississippi River at St. Louis
recently subsided to below flood stage for the first time since
June.
11) Mississippi River watershed 1993 precipitation was the
greatest since 1895 for the following periods: July, June-July,
May-July, and April-July.
12) Rainfall totals have been phenomenal. For example,
Papillion, NE (just south of Omaha) reported 1 inch of rain in 6
minutes during a thunderstorm. Several locations in Nebraska and
other states reported 12-inch rains in 48-hour periods. In
Adrian, MN, after a 7-inch rainfall in a little over an hour, a
3-foot wall of water rushed through the town causing severe
damage, and even ripping away large chunks of asphalt from the
streets. (Keep in mind that 1 inch of rain equals 27,143 gallons
of water on 1 acre of land.) There was even an unofficial report
from New London, IA of 6.5 inches of rain during a 15-minute
cloudburst!
13) The combined totals for June-July are equally impressive.
Wisconsin, Iowa, and Illinois had their wettest June-July period
on record (since 1895), while Minnesota had its 2nd wettest.
Iowa, the Dakotas, and Montana had their wettest July on record,
while Iowa also had its wettest August on record. Following are
some of the more impressive rainfall totals:
Cedar Rapids, IA--34.44 inches for April-July and Salina,
KS--37.22 inches for April-July--both exceeding their annual
average in just 4 months.
Northwest and north-central Missouri generally received
between 15 and 25 inches of rainfall for July, with some stations
receiving 1.5 to 2.5 times the previous record total for July.
(This contrasts with some locations in the southeast bootheel
receiving less than 1 inch for July.)
Record monthly totals of greater than 10 inches (NWS
offices):
June-- July--
Moline, IL (13.21) Concordia, KS (16.75)
Rockford, IL (11.85) Bismarck, ND (13.75)
South Bend, IN (10.86) Grand Isle, NE (10.68)
Waterloo, IA (10.11) Peoria, IL (10.15)
Record June-July combined totals (NWS offices):
1993--
Location New Record Old Record Normal % of Normal
Chicago IL 14.4 11.2--1970 7.4 195
Moline IL 19.0 18.4--1969 9.2 207
Springfield IL 16.8 16.6--1981 6.9 243
Dubuque IA 16.5 15.9--1969 8.2 201
Waterloo IA 21.4 17.6--1990 9.3 230
Concordia KS 23.5 18.8--1967 8.1 290
Grand Island NE 15.6 14.9--1967 6.7 233
Norfolk NE 15.4 13.4--1950 7.7 200
Omaha NE 17.7 14.2--1967 7.2 246
Bismarck ND 18.4 8.2--1963 4.9 376
Fargo ND 12.0 11.8--1975 5.5 218
Grand Forks ND 11.6 11.4--1968 5.6 207
Williston ND 10.1 9.2--1963 4.4 230
Aberdeen SD 13.6 11.3--1939 5.9 231
Huron SD 13.8 13.3--1984 6.0 230
Sioux Falls SD 14.3 13.5--1948 6.1 234
Green Bay WI 13.6 13.2--1990 6.5 209
Other notable amounts:
6/13/93--4 inches in 1 hour in Lenox, IA.
6/23/93--10 inches in 4 hours near Armstrong, IA.
11 inches (during afternoon) in Hamms Park, MN
(9 inches fell in 2 hours).
6/30/93--7 inches in 4 hours in Dickinson and Emmet
Counties, IA.
7/03/93--5 inches in 2 hours in McCook County, SD.
7/09/93--11 inches overnight in Scranton, IA.
7/10/93--7 inches in just over 1 hour in Adrian, MN.
7/17/93--2 inches in 12 minutes in Montgomery County, IA.
12 inches in 3 hours near Baraboo, WI.
7/24/93--10 inches (in morning) near Finley, ND.
July 93--30.3 inches in Worth County, MO (90% of mean
annual precipitation).
8/13/93--9.5 inches (overnight) in Leroy, MN.
Wettest summer (June-August) on record (since 1895),
statewide average precipitation shown in parenthesis:
Idaho (6.08) North Dakota (15.84)
Illinois (19.67) South Dakota (13.27)
Iowa (26.90) Missouri River Basin
Minnesota (17.24) Upper Mississippi River Basin
Montana (9.83) Souris-Red-Rainy Basin
Wettest January-August on record (since 1895), statewide
average precipitation shown in parenthesis:
Idaho (16.39) Minnesota (26.35)
Illinois (36.79) North Dakota (20.68)
Iowa (41.26)
14) Comparison to flooding of 1947: Similarities to this year
include cool spring weather east of the Rockies, wet conditions
from the central Plains to the Great Lakes states, and the
development of major flooding in the upper Mississippi Valley in
late June. However, this year (unlike 1947), heavy rainfall in
the upper Mississippi area continued through July--a month longer
than in 1947. Therefore, the flood crests were higher and lasted
longer than in 1947. The only other time this century that
widespread summer flooding occurred in these same areas was
during June-July of 1951. During the 4 days preceding the 1951
flood, much of eastern Kansas and western Missouri received more
than 10 inches of rain. Although this flooding was confined to a
smaller area (mostly Kansas and Missouri), it claimed 41 lives,
left 200,000 people homeless, and caused a billion dollars in
property damage, with $870 million damage in the Kansas City
area.
15) The attached report (Atch 1--prepared by the Climate
Analysis Center for the "Weekly Weather and Crop Bulletin") is an
interesting study of summer rainfall vs. first freeze occurrence
of the fall. Due to delays in planting caused by the heavy
rainfall in the Midwest, there is great concern about harvesting
being completed before the first fall freeze. In fact, this
growing season thus far (March-August) has been the wettest on
record for the primary corn and soybean belt.
1) The heat wave and drought in the Southeast, although less
costly than the flooding, has been devastating for many of the
area's farmers. During June-July, much of the area received less
than 50% of normal rainfall along with temperatures 3-6 degrees
above normal. The Southeast as a whole recorded the 2nd driest
July on record (since 1895, driest was 1983). Also, the states
of Alabama, Georgia, North Carolina, South Carolina, Tennessee,
and Virginia had their hottest July on record (since 1895). So
far, South Carolina is one of the hardest hit states, having had
its driest June and 6th driest July on record, resulting in the
following losses:
Over 95% of corn crop lost.
Over 70% of soybean crop lost.
Over 50% of wheat crop lost.
Over 25% of tobacco crop lost.
Peach crop production down significantly but not quantified
yet.
1.8 million chickens killed by the heat.
2) Much of South Carolina, North Carolina, Georgia, and
Tennessee are now in the severe to extreme drought category
according to the Palmer Drought Severity Index (PDSI). (The PDSI
uses mathematical formulas to quantify each region's wet or dry
spell.) However, due to unusually wet conditions during the fall
of last year through the early spring of this year, hydrological
impacts have thus far been minimal.
3) The death toll from a heat wave is very hard to calculate due
to the occasional inability to determine if a death was truly
caused by the heat. Deaths that are attributed to 'heat stress'
are often included in evaluations. Preliminary reports indicate
that the death toll now exceeds 100 for the Southeast and
Northeast combined.
4) The monetary value of crop losses are preliminary and still
climbing, but are currently estimated as $264 million for South
Carolina, $165 million for North Carolina, and $500 million for
Georgia. The overall losses for the Southeast will probably
exceed $1 billion, especially if the drought continues well into
the fall. So far, disaster areas have been declared as follows:
South Carolina--all 46 counties.
North Carolina--89 of 100 counties.
Georgia--154 of 159 counties.
5) Some of the temperature records established include (all
values in degrees Fahrenheit):
Asheville, NC (with a 92-year period of record)--25 days in
July with 90 degrees or higher, breaking the old record of 18
days.
Several locations in the Southeast reported 90 degrees or
higher every day in July, including Greenville-Spartanburg, SC;
Chattanooga, TN; and Atlanta, GA.
Columbia, SC--17 consecutive days in July of 100 degrees or
higher.
Atlanta, GA--7 days of 100 degrees or higher in July.
Augusta, GA--47 of 61 days with 95 degrees or higher,
including 21 days with 100 or higher.
Hottest July on record (departure from normal in
parenthesis):
Chattanooga, TN (+6.7)
Atlanta, GA (+6.7)
Philadelphia, PA (+6.5)
Knoxville, TN (+6.3)
Charlotte, NC (+6.2)
Athens, GA (+5.9)
Augusta, GA (+5.6)
Norfolk, VA (+5.4)
Columbia, SC (+5.4)
Greensboro, NC (+5.2)
Greenville-Spartanburg, SC (+5.0)
Beckley, WV (+4.9)
Newark, NJ (+4.9)
Asheville, NC (+4.7)
Richmond, VA (+4.7)
Louisville, KY (+4.7)
Roanoke, VA (+4.6)
Raleigh-Durham, NC (+4.5)
Lexington, KY (+4.4)
Evansville, IN (+4.3)
Erie, PA (+4.2)
Washington-Dulles, VA (+4.1)
Charleston, WV (+4.0)
Cape Hatteras, NC (+3.6)
Washington-National, DC (+3.2)
Tallahassee, FL (+2.0)
Hottest summer (June-August) on record:
Chattanooga, TN (82.0, with 85.2 in July!)
Newark, NJ (79.2)
Hottest summer (June-August) on record (since 1895),
statewide average temperature shown in parenthesis:
Florida (82.3)
2nd hottest summer (June-August) on record (since 1895),
statewide average temperature shown in parenthesis:
New Jersey (74.3)
North Carolina (77.9)
South Carolina (80.7)
6) Some of the records established for drought include:
San Antonio, Austin, and Corpus Christi all recorded no
measurable precipitation for at least 60 consecutive days.
Driest June on record:
Charlotte, NC (.15)
Greenville-Spartanburg, SC (.17)
Raleigh-Durham, NC (.33)
Driest July on record:
Charleston, WV (1.98)
Beckley, WV (1.65)
Greenville-Spartanburg, SC (.75)
Norfolk, VA (.36)
San Antonio, TX (.00)
Dallas, TX (.00)
Austin, TX (.00)
Waco, TX (.00)
Driest summer (June-August) on record (since 1895),
statewide/regionwide average precipitation shown in parenthesis:
South Carolina (7.98)
Southeast region (10.37)
2nd driest summer (June-August) on record (since 1895),
statewide average precipitation shown in parenthesis:
Florida (14.70)
New Hampshire (7.23)
North Carolina (9.43)
Virginia (7.06)
1) So far, the federal government has allocated $5.8 billion in
disaster relief funds for the flood and drought-ravaged areas.
The agencies involved in this disaster include: 1) the National
Weather Service, 2) the Army Corps of Engineers, 3) the Coast
Guard, 4) the Environmental Protection Agency, 5) the Federal
Emergency Management Agency, 6) the Department of Agriculture,
and 7) the Federal Housing Administration.
2) The second attached report (Atch 2--also prepared by the
Climate Analysis Center) dramatizes the 'polarity' of the
conditions experienced across the United States this summer. (On
this graph, the 'wet area' percentages are inverted such that the
true percentage is estimated by subtracting the percent figure on
the vertical axis from 100%.) Due to the persistent trough west-
ridge east pattern, a large portion of the country has been, and
continues to be either unusually moist or unusually dry. At the
end of August, this graph shows about 34% of the country to be
unusually moist (unusual to extreme moist spell), and about 32%
of the country to be unusually dry (moderate to extreme drought)-
-thus leaving only about a third of the country with near normal
conditions. For example, from April through August, Des Moines,
IA received 40.18 inches of rain (compared to normal of 20.18),
while Greenville-Spartanburg, SC received only 7.50 inches
(compared to normal of 21.64 inches). Similarly, Salina, KS
received 42.56 inches for the same 5-month period, while only
9.64 inches fell on Charlotte, NC.
3) To add insult to injury, preliminary data shows this summer
to have produced 791 tornadoes across the country--a new record.
However, the final count is always slightly lower than the
initial total, so this is not yet an official record. Also,
there have been several reports of softball-size hail in the
areas hit by severe flooding, thus adding to the destruction.
Some of the thunderstorm radar echo tops reached over 70,000
feet, being fueled by surface dew points that peaked in the low
80's. These 'supercell' storms generated some of the tornadoes
mentioned above, and in some cases, produced microburst winds
(non-tornadic) exceeding 100 MPH.
4) The National Climatic Data Center in Asheville, NC has
several publications and digital datasets which provide much more
detail about the events of this past summer. For information and
ordering instructions, please contact the Climate Services Branch
(phone 704-271-4800, fax 704-271-4876, internet
orders@ncdc.noaa.gov)
During the past 12 months, the U.S. has been hit by 4 major
weather 'disasters'--1) Hurricane Andrew, 2) Hurricane Iniki, 3)
the March '93 "Storm of the Century," and 4) the flooding and
drought of this past summer. The preliminary damage/costs
estimates for these 4 events total nearly $45 billion. The list
below shows those weather events since 1980 which have caused at
least $1 billion in estimated damage/costs (including direct +
indirect impacts). These disasters have placed a great strain on
the affected federal, state, and local governments as well as the
insurance industry. In fact, the past 6 years (1988-1993) have
produced 7 weather-related disasters exceeding $1.0 billion with
total estimated damage/costs of $93.4 billion.
Billion Dollar U.S. Weather Disasters 1980 - Mid 1993
1. Severe Flood--Summer 1993. Central U.S., estimated $12.0
billion damage/costs so far, estimated 48 deaths.
2. Storm/Blizzard--March 1993. Eastern U.S., estimated at least
$6.0 billion damage/costs, estimated 270 deaths.
3. Hurricane Iniki--September 1992. Hawaiian island of Kauai,
about $1.8 billion damage/costs, 5 deaths.
4. Hurricane Andrew--August 1992. Florida and Louisiana, about
$25.0 billion damage/costs, 58 deaths.
5. Hurricane Bob--August 1991. Mainly coastal North Carolina,
Long Island, and New England, $1.5 billion damage/costs, 18
deaths.
6. Hurricane Hugo--September 1989. North and South Carolina,
$7.1 billion damage/costs, 57 deaths.
7. Drought/Heat Wave--Summer 1988. Central and Eastern U.S.,
$40.0 billion damage/costs, estimated 5,000 to 10,000 deaths.
8. Hurricane Juan--October-November 1985. Louisiana and
Southeast U.S., $1.5 billion damage/costs, 63 deaths.
9. Hurricane Elena--August-September 1985. Florida to
Louisiana, $1.3 billion damage/costs, 4 deaths.
10. Hurricane Alicia--August 1983. Texas, $2.0 billion
damage/costs, 21 deaths.
11. Drought/Heat Wave--June-September 1980. Central and Eastern
U.S., $20 billion damage/costs, estimated 1300 deaths.
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