David Reed, Hydrologist In Charge | Vol. 8 No. 1, Autumn 2004 | Ethan A. Jolly, Editor |
2004 Hurricane Season | Know Your
River Systems: Red River Basin |
From the HIC | ||
With less than a month remaining, the active 2004 hurricane season is about to come to a close. The LMRFC forecast area in western North Carolina and Eastern Tennessee experienced widespread major flooding with two locations recording a flood of record. We provided critical forecasts and services to our customers in this area. Congratulations to the LMRFC staff for a job well done. Our forecasts and activities during this period are documented in this issue. We have ended the busy fiscal year 2004 and are now in fiscal year 2005. Last fiscal year, we implemented AHPS services at 25 locations in the eastern half of the Tennessee River Valley and completed a significant number of model calibrations to support this implementation. We plan to complete all the necessary calibrations and model development to implement |
these services at an additional 27 locations in western Tennessee and northern Mississippi this fiscal year. This development and implementation will take a big part of non-operational time. We will be doing this work along with issuing critical river and flood forecasts and continuing to implement new daily forecast locations and services to meet all customer needs. Again, congratulations to the LMRFC staff for their fine efforts. We expect a busy year in 2005. We always like to hear from our customers about their needs. Please do not hesitate to call us and let us know how we are doing or if there are other services you will need.
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Impacts of 2004 Hurricane Season | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
The relatively dry conditions observed across much of the LMRFC area during the months of July and August changed dramatically in early September with Hurricane Frances which made landfall in Florida on September 5th and traveled up through the southeastern states. Heavy rains fell in the eastern portions of the LMRFC over the southern Appalachian Mountains of Tennessee and North Carolina producing major river flooding. Frances was soon followed by Hurricane Ivan which made landfall on September 16th and Hurricane Jeanne which made landfall on September 25th. Ivan and Jeanne brought additional rainfall to already saturated areas in the mountains of east Tennessee and western North Carolina resulting in significant flooding along the French Broad, Pigeon, and Tuckasegee Rivers and over portions of eastern Tennessee. Hurricane
Frances
As Frances continued inland, it produced heavy rainfall across the southeast U.S. The total accumulated rainfall from Frances is shown in Figure 1. The heaviest rains fell over Florida and southern Georgia and over the Appalachian Mountains of North Carolina and South Carolina. Isolated rainfall amounts between 10 and 14 inches occurred over parts of western North Carolina in the LMRFC area. Major flooding, including three modern day records, occurred along the French Broad and Pigeon Rivers. Minor flooding occurred along the Tuckasegee and Nolichucky Rivers. The crest value and type of river flooding observed are shown in Table 1. Hurricane
Ivan |
The rainfall associated with Ivan as it moved through the southeastern U.S. is shown in Figure 2. The heaviest rains associated with Ivan were located along the border of Alabama and Florida where 12 to14 inches of rainfall was observed. As Ivan crossed into Tennessee as a tropical depression, it produced 8 to 10 inches of rainfall extending from northern Alabama and Georgia into central Tennessee and another 8 to 12 inches of rainfall along the Appalachian Mountains of North Carolina and South Carolina. The rainfall over the Appalachian mountain region fell in many of the same areas that had already seen significant rainfall from Frances earlier in September resulting in significant flooding along the French Broad River and over parts of east Tennessee. As shown in Table 1, many of the same locations which saw flooding with Frances received additional flooding from the rains from Ivan. After moving off the east coast of the U.S., the remnant low from Ivan moved southwestward, eventually crossing the Florida peninsula and moving into the Gulf of Mexico. Ivan reformed as a tropical storm and made its second and final landfall in southwestern Louisiana on September 24th. It moved inland into east Texas where it dissipated. Rainfall associated with Ivan’s second landfall was relatively low with only isolated areas in eastern Texas and southwestern Louisiana receiving 3 to 7 inches of rain. No river flooding was observed in the LMRFC area from this rainfall. Hurricane
Jeanne
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Know Your River Systems: Red River System | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
The
Red River, one of the longer rivers in the United States, traverses about
1200 miles with its headwaters forming in the Texas Panhandle near the
Amarillo area. It flows eastward forming the Oklahoma/Texas border and
continues across extreme southwest Arkansas. The River then turns south-southeast
and continues in a general southeasterly direction across northwest Louisiana
to east central Louisiana and ends above the confluence of the Lower Old
River and the Atchafalaya River north of Simmesport, LA. The entire Red
River basin has a drainage area of over 91,000 square miles and includes
the larger tributaries of the Sulphur River, Cypress Bayou, Bodcau Bayou,
Bayou Dorcheat, Black Lake Bayou, and the Ouachita/Black Rivers. The Red River’s channel bed below Fulton contains of sand and reddish silt from which the River gets it name. During low flow conditions, large sandbars are visible along the numerous bends of the River. The scenery alternates between remote bottomland woods and an occasional small town. At high stages, normally from December to June, the main channel is continually shifting and changing course, eroding one bank and making deposits on the other. Since the reach of the River between Fulton and Shreveport is densely wooded, fallen trees are frequent and become an obstruction to navigation unless removed. Average annual rainfall over the area ranges from 35 inches over northeast Texas to near 55 inches where the Red flows into the Atchafalaya. |
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