VIRGINIA FLOODS

By Barbara McNaught Watson

        There are four basic types of floods that afflict Virginia: coastal flooding, urban flooding, flash flooding, and river flooding. Coastal flooding usually occurs with the storm surge of a hurricane (see chapter called Virginia Hurricanes) or with a "Nor'easter", an intense low pressure system that moves slowly up the coast with strong onshore winds. While the hurricane season goes from June through November, Nor'easters occur from September through March and are generally considered a winter-time storm (see chapter called Virginia Winters). Urban flooding occurs in heavily paved areas. Pavement does not allow water to be absorbed into the ground thereby increasing the speed and amount of water run-off . If areas are without proper drainage, or storm drains become clogged, then streets become streams and water gathers in low-lying areas turning them into pond. If it rains hard enough, underpasses can rapidly fill trapping motorists and streets can accumulate enough water to submerge cars or carry them wherever the water flows. This chapter will focus on flash flooding and river flooding, Virginia's deadliest weather duo.
        Flash floods occur in a short period of time - a "flash". Rain falls at such a high rate that water does not have time to be absorbed into the ground. It flows downhill into ditches, lowlands and small streams. As the heavy rain continues, ditches overflow, drains backup, water ponds in lowlands and streams rise over their banks. Streams and creeks can become raging rivers in just hours. People are often caught off guard, especially motorists. Half of flash flood deaths in the United States are in automobiles. If you come upon water flowing across a road, do not enter it. Find a new route. It takes a surprisingly small amount of water to make a car float. Just one foot of water can displace 1500 pounds. Also, if you can not see the road beneath the water, then you do not know how deep it is. The road or bridge may no longer entirely exist or may collapsed with  the added weight of the vehicle.  Many people think that they can pass through the water in their vehicle only to have it stall at the deepest point. The water often continues to rise and sweeps the car away. If lucky, occupants are rescued by emergency response people whose lives are now also at risk as they try to make the rescue. People need to ask themselves if this is worth the risk of entering the water or is it better to just turn around.
        River floods occur when heavy rains fall over a large area. In many cases in Virginia, it begins as widespread flash flooding of small streams. About 60% of Virginia's river floods begin with flash flooding from tropical systems passing over or near the state. A recent example was Hurricane Fran in September 1996. The flash flood waters in the streams and creeks flows into the larger rivers and flooding can occur for the next couple of days as the bulge of water progresses down the length of the river. River flooding also occurs as a result of successive rainstorms (as seen in the widespread and prolonged flooding in the mid-west during the summer of 1993). Rainfall from any one storm is not enough to cause a problem, but with each successive storm's passage over the basin, the river rises until eventually it overflows its banks. If it is late winter or spring, melting snow in the mountains can produce added runoff that can compound flood problems. The most recent example of this was flooding in January 1996 with a rapid thaw of the 2 to 4 feet of snow that had fallen over the previous two weeks.
        On the average, 150 people are killed nationally in floods each year. About 75 percent of deaths occur at night. The nighttime maximum is likely due to a combination of heavy rain-producing thunderstorms during the late hours of the day and poor nighttime visibility. Typically, these late night rain producers are associated with tropical systems or a cluster of thunderstorms which remain stationary or continuously redevelop or move over a given area. Sometimes these systems are as big as a state and are called "mesoscale convective complexes" or MCCs for short. While most flash floods are associated with thunderstorms, a dam break can also cause a flash flood from the sudden release of water. The dam may fail due to heavy rains as in the case of the Timber Lakes Dam in Bedford County, VA on June 23, 1995 or a structure or mechanical failure could lead to a flash flood with no rain involved.  Ice dams can also cause flooding in Virginia. The month of December 1989 was cold enough that rivers froze over in Northern Virginia. In January, a thaw began, the ice broke and began to flow down river. The Shenandoah River had several ice dams that formed at sharp bends in the river or up against bridges. One dam on the I-66 bridge backed water up above flood stage into Front Royal. Another ice dam near Fredericksburg caused minor flooding on the city's waterfront. If a ice dam gets big enough, not only can flooding occur from water backing upstream, but a sudden release of the jam will cause a flash flood downstream.
        Most of Virginia's biggest floods have been associated with hurricanes, tropical storms, and their remnants passing over the commonwealth. The biggest cloudburst on record occurred in Guinea, Virginia on August 24, 1906 when 9.25 inches of rain fell in just 40 minutes!  Virginia's worst disaster and flash flood was associated with the remnants of Hurricane Camille on August 20, 1969 when 27 to 30 inches of rain fell on the mountains of Nelson County.  Rarely does a tropical system pass over the state without some portion of the commonwealth receiving a heavy rain and flood. These storms are often localized to a portion of the state such as Hugo in September 1989 which caused flooding on the New River in Southwest Virginia, but the remainder of the state was dry. Only in rare cases such as Agnes in June 1972 does the entire commonwealth experience flooding at the same time. Seven of the top ten river floods listed below were related to tropical moisture brought into the state from hurricanes, tropical storms, or remnant systems. The other three were snow melt and spring rains.

Virginia's Top Ten Worst River Floods (20th Century)

Terms: "flood stage" is the height of the river or stream when property damage begins. The river may already be out of its banks and into lowlands along the river. Once the water rises above flood stage, damage is expected. The "flood crest" moves like the crest of a wave down the river. It is the highest height or stage that the flood waters reach during an event.

"In the spring of 1771 the lowlands of all Virginia rivers east of the Alleghenies were inundated by destructive floods. This unexpected tragedy was probably the most devastating act of God which has been experienced in Virginia during the three and one-half centuries since the English planted their colony at Jamestown. Many islands were torn to pieces, hills of sand thrown up, channels stopped, the face of nature almost changed.

While not a cloud was to be seen in the skies above the Tidewater, torrential rains deluged the central Blue Ridge Mountain region throughout ten or twelve days in May 1771. Rivers which drained this general area - the James, the Rappahannock, and the Roanoke in particular - overflowed when unprecedented quantities of water were funneled into their channels. The Shenandoah, Potomac, and York rivers seem to have swollen to a lesser degree, but whatever damage they did was overlooked in the colony's greater concern over the more extensive destruction done by the other three.

For sixty hours the James river rose continuously, as much as sixteen inches per hour. On May 27, a ship anchored near Warwick in Chesterfield County, a few miles below Richmond, which made soundings from the first perceptible rise, found itself riding a crest forty feet higher than the common tides. Other observers claimed that this fresh was twenty feet higher than the one in May 1766, and ten feet higher than those which had come in 1720 and 1724. Richard Adams saw from his porch a flood "40 feet perpendicular." So dreadful was it, he remarked, that a truthful description of it would not seem credible to anyone who had not seen it with his own eyes. Old Joe, an honest and well-known Negro at the falls of the James near the little town of Richmond, said that the water climbed fifteen feet above the crest of the worst flood remembered in the tradition of neighboring Indians. The Rappahannock River was reported in The Gentleman's Magazine of London to have risen twenty-five feet higher than it had ever been known to be.

Swept from their foundations, houses floated down the rapid currents. Despairing people trapped on these makeshift crafts shouted pitifully for help, but no attempts at rescue could be ventured. Wine casks, hogsheads of tobacco, furniture, trees, lumber, and even large warehouses were borne seaward by the swirling waters.

All told, one hundred and fifty persons were said to have lost their lives. Many others had narrow escapes.

Both in the Piedmont and in the Tidewater property losses were disastrous. Thomas Jefferson lost his gristmill at "Shadwell" on the Rivanna River. Everything was swept off Farrar's Island.... Eighty acres of rich topsoil on this farm were buried under ten to twelve feet of sand overlaid by rocks flattened smooth as if by a modern steam roller. ...at Elk Island...nothing being saved but the people and five horses. It is more meaningful to express the losses of this one estate in terms of more than seven hundred livestock, nearly a hundred farm buildings, and unknown quantities of grain and tobacco. At another plantation, located where the Rivanna merges with the James, fourteen Negroes were drowned and only one of forty houses was left standing.

How much destruction was done in the Valley it is impossible to ascertain, but one surviving record indicates that the James River wreaked havoc even west of its passage through the Blue Ridge. John Howard of Botetourt County lost all of his growing crops, all but one of his tobacco houses, his corn house and the feed stored therein, and some of his livestock. It was only because of "the great goodness of God that my People are all alive," he wrote thankfully.

Floods are dirty things, and this one was no exception to the rule. When the rivers receded, carcasses, trees, and other debris were found to be matted together in some places to heights of twelve and even twenty feet. These confused masses of litter issued such a stench that there was no undoing them. As may have been expected, a "sickly" summer followed."

March 17-18, 1936: During the period March 9-22, successive storms crossed the eastern region of the U.S. with floods occurring from Virginia to Maine. A total of 150 to 200 lives were lost and damage was in the millions. In Virginia, the Potomac, Shenandoah, Rappahannock, James, and York Rivers flooded. Most large flood events in Virginia are associated with tropical systems. This flood was the largest non-tropical flood event. The winter of 1935-1936 was marked by long-continued periods of low temperatures and heavy snowfalls. In December, it was estimated that areas in the northern Blue Ridge Mountains exceeded 40 inches of snow. Some snow melted during a mild January, but more fell in late January to mid-February. March began with warm temperatures and a thaw. The first rainstorm came in the second week with up to three inches falling. The rains melted the snow, adding an equivalent of one to two inches of rainfall. This caused the rivers to rise and set the stage for the next rain event.

The primary flood-producing rains came March 17 and 18 when a storm, drawing moisture from the Gulf of Mexico, tracked right across Virginia. It dumped an additional six inches of rain on top of the already saturated soil. The North Fork of the Shenandoah crested eight feet above flood stage in Rockingham County. At Front Royal, the Shenandoah flooded the city rising to 14 feet above flood stage. The Potomac River in Washington, D.C. rose nine feet above flood stage flooding portions of Arlington and Alexandria including the old airport (where the Pentagon is now located). The fresh water inundation on the Lower Potomac and tributaries killed thousands of bushels of oysters and seedlings. In Culpeper, the Rapidan crested at over five feet above flood stage and in Fredericksburg, the Rappahannock flooded. The James River, at Richmond, reached 26.5 feet (18.5 feet above flood stage) causing serious flooding to the city's industrial and business sections.

April 1937: Just one year after the record flood of March 1936, another major flood struck Virginia. Heavy rains caused widespread flooding over all but southwest Virginia. The Rappahannock Basin was hit hardest. Fredericksburg saw its worst flood since 1889 when the river swelled to 30 feet above normal. Three bridge spans were lost, home in low areas were partially submerged and a score of gasoline storage tanks were swept away. Four young Culpeper residents died in Madison County when their car plunged off a bridge at Locust Dale into the Robinson River. The approach to the bridge had been washed away by the flood waters. Another person was lost in Amelia County when their car dropped into the river where a bridge approach was washed out. A sixth person was drowned when a roadway over a dam collapsed. Flooding on the Potomac was not as bad as the previous year, yet the river reached 14.3 feet at Wisconsin avenue and portions of Alexandria and Arlington again flooded. Total damages to roads and bridges in Virginia came to nearly a half a million dollars. Agricultural losses came to over a million dollars in Northern Virginia alone.

October 1942: Torrential rains fell from October 12-16 in Northern Virginia causing the worst river flood in the history of the state. The hardest hit was the mid portion of the Rappahannock River and the Shenandoah River. On the Rappahannock, damages came to $2.5 million (1942 dollars) and most of that was in Fredericksburg, where the river rose to 41 feet (27 feet above flood stage). On the Shenandoah River, a stage of almost 50 feet was reached at Riverton on the morning of the 16th. Flood stage is 22 feet and it broke the record set by the March 1936 flood by 12 feet! Flood losses on the Potomac River were $4.5 million. The Potomac at Washington reached 17.6 feet (flood stage is seven feet). Areas of Alexandria and Arlington were seriously flooded. Flooding was not quite as serious on the James River, yet the flood crest in Richmond reached 16 feet above flood stage.

Ten to 12 inches of rain fell from Fredericksburg to Warrenton. Seventeen inches were recorded in Front Royal. In Shenandoah National Park, along Skyline Drive, rainfall totals reached 18 to 19 inches! To the south, Nelson County received 16 inches. Another maxima of 12 to 16 inches fell from near Paw Paw, West Virginia south along the mountains into Highland and Bath Counties of far western Virginia. Highways and bridges were washed away. Over 1,300 people were left homeless in Albemarle, Spotsylvania, Stafford and Warren Counties. Miraculously, only one person died. Transportation was interrupted for three days. Severe damage occurred to Virginia crops: peanuts, cotton, sweet potatoes, soybeans, shocked corn and late hay. The heavy rains caused a million bushels of apples to drop before they were picked.
 

June 1949: Severe flash flooding struck the southern Shenandoah Valley of Virginia and Potomac Highlands of West Virginia in June 1949. High pressure over New England combined with a tropical low near Georgia to set up a flow of moist, tropical air from the Virginia Coast westward against the east slopes of the Appalachians. As the air lifted along the mountain slopes, rain began. Flood-producing rains occurred from mid day on the 17th into the morning of the 18th while the tropical low moved from the North Carolina Coast to southern Virginia. In Virginia, the heaviest rain fell in the Bridgewater-Stokesville area of Rockingham and Augusta Counties. Witnesses say that rain fell in sustained torrents from mid afternoon to past midnight. Car headlights could not penetrate the rain more than 5 feet. At the North River Dam Station nearly 10 inches of rain was recorded over three days with 7.75 inches of it falling in a 24 hour period beginning the morning of the 17th. However, much greater rainfall amounts fell in the hardest hit area. Rainfall was so great in the upper reaches of the Little River that it caused large landslides on the steep slopes. The North River and it tributaries above the mouth of the Dry River were all at record breaking stages. Interviews (by the Division of Water Resources) with the oldest inhabitants established that this flood was higher than the 1877 flood. The USGS gage on the North River near Burketown (downstream from Bidgewater) indicated a crest of 36.3 feet, about 4 feet higher than the October 1942 flood crest. A preliminary report by the Weather Bureau read as follows:

Stokesville, Va., where heavy damage occurred, is located just below the confluence of the Little River and the North River. It received the combined flow of both streams, which apparently peaked at about the same time. From eyewitnesses' accounts, this combined flow made such a sudden rise that it gave the effect of a "wall of water" traveling down the channel and causing extreme damage all the way to Bridgewater.

The path of the high-intensity rainfall also included the headwaters of Briery Branch, causing a great flood on this stream. The town of Bridgewater, Va., received the flood waters from the combined North River -- Little River -- Briery Branch drainage areas, apparently with their peak flows nearly simultaneous.
 

The Stokesville area is a community of 76 families. This area saw 14 homes destroyed, 29 homes damaged, 20 brooder houses destroyed, 2 barns and 75 smaller out-buildings lost to flood waters. Another 31 smaller buildings, two gas stations, and an undetermined number of cars and trucks were lost. Several hundred chickens and turkeys and 36 head of livestock were lost. Total damages to this small community came to nearly half a million dollars. About 25 homes were lost along Briery Branch. The town of Bridgewater had a population of around 1000. Here, three lives were lost and damages totaled nearly one million dollars. Some 50 homes were flooded and one was destroyed. Municipal installations such as water supply and sewage disposal were heavily damaged. Power and phone lines were lost as well as over 50 vehicles. The Highway Department listed damages at a quarter of a million dollars. A 240-foot bridge at Mt. Solon in Augusta County and two 100-foot bridges aCROSS THE NORTH rIVER IN rOCKINGHAM cOUNTY WERE LOST. Practically the entire highway along the North River between Towers School and Stokesville was destroyed. Agricultural losses from the flood were half a million dollars. Total flood damage was a little over 2 million dollars.

August 1955, Connie and Diane: On August 12, Hurricane Connie dropped a record 8.79 inches of rain on Richmond. Connie moved up the Chesapeake Bay on the thirteenth, across Baltimore and into Pennsylvania. The rains produced by Connie saturated the soil and set the stage for Hurricane Diane. Hurricane Diane, just five days after Connie, moved across central North Carolina, central Virginia, Washington, D.C. and into Pennsylvania. Diane dropped an additional 10 inches of rain on the Blue Ridge Mountains. East winds in advance of the storm lifted the heavy moisture-laden air into the mountains. The heaviest rains again fell along Skyline Drive. Many areas, from Danville to Fredericksburg to Winchester and Staunton, set new record rains for the month of August. Luray recorded 8.82 inches of rain on the 18th from Diane, setting a new 24 hour record for the site and had a new monthly record near 20 inches. Big Meadows, in the mountains southeast of Luray, set a new record for August with near 24 inches.

Except for some local areas, river flooding was not as severe as the 1942 and 1936 floods. The heavy rains resulted in flash flooding along the piedmont and over the Shenandoah Valley. Water flowed into nearby rivers causing the heaviest flooding on the Shenandoah and the Rappahannock rivers. The Rappahannock River crested in Remington at 8.5 feet above flood stage setting a new record and at Fredericksburg, it crested 11.5 feet above flood stage. In Richmond, the James River crested nine feet above flood stage but well below the flood of 1936. In Rockingham County, the Shenandoah River crested one to two feet above flood stage (nine feet below the 1942 flood) and downstream, at Riverton, it crested near 30 feet (7 feet above flood stage).

August 19-20, 1969: Hurricane Camille made landfall on the Louisiana Coast and maintained hurricane strength for 150 miles up the Mississippi Valley. The storm turned east and headed for Virginia. It tapped into the warm moisture-rich air over the southern Gulf Stream and drew it northwest toward its center and toward the Virginia Mountains. Thunderstorms began to grow and it started raining. The storms formed a band with each thunderstorm following the one before it as they rose up the mountain slopes between Charlottesville and Lynchburg. An area 100 miles long and 25 miles wide received more than 10 inches of rain. In Nelson County, the storm total came to 27 inches and unofficial rain total was estimated at 31 inches! Rain from Camille produced the worst flash flood in Virginia's history. It was so devastating that 117 people died, all communications were cut off to the outside world and damages came to over half a billion dollars.

The following stories were obtained from the Charlottesville Daily Progress and published in the Southern Climate Review in the Autumn 1989 addition:

Wayne Oliver, of Lovingston, awoke around 3 a.m., heard some unusual noises, decided to get out of bed and have a look around. Eight inches of water were on the bedroom floor. "We'd been having some trouble with the water system and I thought maybe a pipe had burst, so I went to check it out. That's when the house started moving." The wife and two young children huddled on the bed while Wayne fought to open the water-swollen attic door and lift them above the rising water. "The bed was floating and it got higher and higher and you could feel the house moving. The boards were cracking and popping and first the floor came apart in the kitchen and then it came apart in the bedroom and then the bed hit the ceiling with me on it and the whole house came apart! It threw me into the water and carried me away and I couldn't hold them any more. I never saw them again.... I don't know how far I drifted. There were boards hitting me and I was groping for them but nothing would hold me up until I finally came up on a piece of the house. I think it was the livingroom." Mrs. Oliver was washed a mile from her home. Her husband wound up in a tree a half mile away. The children were never found.

A mother and child stayed in their home as it was torn from its foundation and floated over seven miles downstream. They were unharmed.

Dora Morris lived at the head of Davis Creek where its average depth is a few inches. In virtually continuous lightning, she estimated it had risen to a height of 50 feet. "The awfullest roar. It was a horrible sound. I suppose it was the landslides and the trees tumbling down the hollow, tearing at everything." She said it lasted four hours.

By 1 a.m., August 20, the amount of rain was enough to undermine the forest floor, and mudslides - soil, rock, boulders, trees, and some inhabited houses poured down the ravines. At some points, these slides were blocked and created temporary dams that impounded acres of water. Finally, the dams would give way sending torrents down the creeks into Tye, Piney, and Rockfish Rivers. For five miles down Davis Creek, logs were piled 30 feet high.

Curt Matthews smelled it coming. The scent of crushed pine pitch, amidst the roar of the mudslides, invisible in the storm, was what saved his life. At 1 a.m. "I had gone in to lay down for a while, and when I came back out on the porch, I smelled the unusual odor of bark and sap and green timber. I'm in the logging business and I know that smell, but I never in my life smelled it so heavy, even in a sawmill. The air was like sticking your head in a sack of bark. Finally, I couldn't stand it any longer and I went to wake up my wife and told her we had to get out. She didn't want to go and it took me 20 minutes to get her and the child ready. But in 20 minutes, the water rose from three to eight feet in my yard.... It must have been all these trees coming apart and washing down the hollow that I smelled. I guess I was one of the lucky ones." His home and land disappeared without a trace, but the family got out in time.

Samuel Johnson of Massies Mill was washed through the eaves of his two-story house at 3 a.m. He rode the water a half mile downstream and lodged in a tree. "The house went away like a paper bag bursting." He spent over six hours in the tree with "not a rag on my body...just the same as I came into the world." The other family members in the house did not survive the night.

Mr. McQuary of Rockfish: "The first thing I heard was this water on my porch. I kept fussing with my wife, but she didn't want to leave her belongings. There was this rumbling...like thunder...and the ground trembling. As my wife stepped off the porch, the house began to go...rocks and water just squished it off...we managed to get away." Within a half hour, "the thundering came back and big rocks and trees came down.... All I saved is what I had on my back."

June 1972, Agnes: Hurricane Agnes, in its tropical storm stage, caused torrential rains over Virginia and the Mid-Atlantic States. In Chantilly (near Dulles Airport), 16 inches of rain fell. All rivers in Virginia were affected. Ten inches of rain fell over northern Virginia resulting in widespread flash flooding and major flooding on the Potomac River. New records were set on the Rapidan and Rappahannock Rivers. In Lynchburg, the James River crested eight feet above flood stage. In Richmond, the river crested 6.5 feet above the old record flood marks dating back 200 years. Water supply and sewage treatment plants, along with electric and gas plants, inundated and were partially shut down. Four of the five bridges crossing the James were closed. A 200 block area of downtown Richmond was swamped and closed off for several days. Flooding occurred on the Appomattox River with Farmville suffering its worst flood in history. The Dan River at Danville and the Roanoke River in Roanoke exceeded previous record flood stages set in August 1940. A total of 63 counties and 23 cities qualified for federal disaster relief. There were 13 deaths and $222 million in damages. Sensitized by Camille, quick evacuation saved lives. Numerous homes were destroyed, 600 roads went underwater and 103 state highway bridges were washed out or damaged.

November 1985: This was the most recent major flood in Virginia causing 22 deaths and nearly $800 million in damage. Extensive flooding also occurred in eastern West Virginia and western Maryland. Heavy rains began on the fourth of November causing flash flooding. Roanoke recorded a record 6.63 inches of rain in 24 hours. The Roanoke River rose seven feet in one hour and 18 feet in six hours. It crested at 23 feet on November 5 - Election Day. Eight feet of water stood in downtown Roanoke causing extensive damage. Mobile homes were swept down the river. Boats and helicopters were used to rescue people from the cold waters and pluck them off roof tops.

Flash flooding occurred in normally dry hollows. The flood waters carried tremendous amounts of debris which wiped out bridges and left channels filled with rocks. In Lynchburg, the James River reached a new record flood stage: seven feet above the old water marks. Stored tobacco valued at $8 million was lost in several warehouses along the James. Canisters of deadly chlorine gas were washed into the river from a plant near Lynchburg. In Richmond, the river flooded several blocks of commercial and industrial buildings.

FEMA (Federal Emergency Management Agency) declared 50 jurisdictions disaster areas, and 4,331 people applied for temporary housing. A total of 1.7 million people were affected by the flooding with the majority in Roanoke, Salem, Lynchburg and Richmond. Nineteen election polling stations had to be moved due to the flooding and it should be no surprise that the turn out was considered poor.

June 1995: This was the worst flash flooding in Virginia since Camille in 1969. It is estimated that near 20 inches of rain fell in southwestern Madison County in less 12 hours.

January 1996:
 

September 1996:
 
 

Disaster Report: June Floods of 1995: Virginia Piedmont, Dept. of Commerce, NOAA, NWS, May 1994.

Preliminary Report of Flood Damage: Potomac Watershed, Virginia: Stokesville -

Bridgewater Flood, June 1949, US DOC, Weather Bureau, June 1949.

Flood of June 1949 in Stokesville-Bridgewater Area, Bulletin 10, Commonwealth of

Virginia, Dept. of Conservation and Development, Division of Water Resources, Charlottesville, VA, 1950.

David Ludlum. The American Weather Book. Boston: Houghton Mifflin Company, 1982, pp. 9-10, 16, 29-31, 54.

"The Great Fresh of 1771": article in the Virginia Cavalcade, Autumn 1951.

Storm Data, Dept. of Commerce, NOAA, NWS.

East Coast Storm: March 5-9, 1962 - A Preliminary Report and Special Weather Bulletins Issued. US DOC, Weather Bureau, March 1962.

*New York Herald Tribune, New York, NY, April 27, 1937.

*The Evening Star, Washington DC, April 28, 1937.

*Journal, Sioux City, IA, May 1, 1937.

Local Climatic Data for Washington, DC. Dept. of Commerce, NOAA, NWS, 1994.

Local records from the Washington DC Forecast Office, Weather Bureau, April 1937.