Drought conditions persist over much of the LMRFC area. Rains have lessened the severity of the drought but we are still in a critical situation. As defined by the Drought Mitigation center, most of the LMRFC area is experiencing severe to extreme conditions. To provide more information, we will focus on the effects of the drought in this issue.

Our procedure development efforts continue at a fast pace. We are developing more graphical products to provide information to

our users in a more usable manner. Efforts are underway to provide information to the Weather Forecast Offices to support short-term backup, and we are preparing for the upcoming flood season by reviewing all forecast procedures. It has been a busy time for the office despite the drought conditions.

We will continue to improve our forecast techniques and work with our cooperators to provide better products and services. Any comments and ideas are greatly appreciated.

- Dave Reed

There has been much talk and discussion of the ongoing drought situation across much of the U.S. during the past two years. The Southeast U.S. and, hence, the LMRFC area, has seen significant impacts as a result of the ongoing dry conditions. After two to three years of less than normal rainfall over much of the area; low reservoir levels, record or near record low river stages and flows, and receding aquifers are some of the more noticeable, hydrologic impacts. Agriculture, wildlife, and commerce are also impacted by the drought conditions.

As shown in Figure 1 (U.S. Drought Monitor for Oct 31, 2000), severe to exceptional drought conditions exist over much of the LMRFC area; including, all of Mississippi and Alabama, most of Louisiana, the west one-half of Arkansas, the south one-half of Tennessee, western North and South Carolina, and north Georgia. Other areas within the LMRFC area are, at best, considered abnormally dry. Currently, the driest conditions exist over west central Arkansas, north and southeast Mississippi, and north Alabama.

Figure 1: US Drought Monitor for October 31, 2000

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Precipitation has been below to much below normal over the area for the past two years. Figure 2 shows that for the 12 month period ending October 2000, most of the LMRFC area is experiencing a precipitation deficit. Approximately 75% of the area was 10 inches or more below normal for the period with south Louisiana, south Mississippi, and portions of south Alabama having deficits of 20 inches or greater. Station rainfall data (Table 1) from January 1 through October 7, 2000 show deficits of 4 inches to 25 inches over much of the same areas. The Palmer Drought Index (PDI - Figure 3) shows a pattern consistent with the rainfall deficit figures.

Figure 2 : Precipitation Deficit for 12 Months Ending October 2000

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Table 1: Year to Date (10/7/2000) Precipitation For Selected Stations in the LMRFC Area
State	Station	Total (Inches)	% of Normal	Departure (Inches)
Alabama	Mobile	27.6	53%	-25
	Huntsville	29.4	67%	-14
Arkansas	Little Rock	26.9	72%	-10
	Fort Smith	26.4	86%	-4
Louisiana	New Orleans	24.5	50%	-24
	Baton Rouge	24.6	51%	-24
	Lake Charles	34.0	80%	-8
	Shreveport	40.2	117%	6
Mississippi	Jackson	30.4	73%	-10
	Meridian	26.6	61%	-17
	Tupelo	28.2	67%	-14
Missouri	Cape Girardeau	31.9	90%	-4
	Springfield	26.8	80%	-7
N Carolina	Asheville	25.1	67%	-12
S Carolina	Greenville	28.0	70%	-12
Tennessee	Memphis	28.0	72%	-11
	Nashville	32.4	89%	-4
	Chattanooga	37.4	91%	-4
	Knoxville	36.7	109%	3
Texas	Dallas/FTW	21.4	80%	-5

Figure 3 : Palmer Drought Index

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Impacts of the drought are seen and felt in numerous ways around the area. Water levels along the White River system are the lowest in many years. Most of the Corps of Engineers' (COE) reservoirs in Arkansas are at 75% or less of their seasonal pools and many stages along the Black and White Rivers are near record low levels (See Table 2). In Mississippi and Louisiana, although COE reservoirs in the Yazoo River system of north Mississippi are at 100 % of seasonal pool, observed flows along the Yazoo River are between 58% and 70% of normal (Table 3). Along the Red and Ouachita Rivers in Louisiana observed flows are running between 12 % and 60% of normal.

On the lower Mississippi River between Arkansas City, AR and Natchez, MS the flow is 60% to 80% of normal. Of particular note is that the stage at Vicksburg, MS has been below normal for 245 of 293 days this water year and that the `spring crest' of 29.4 feet was the third lowest seasonal high on record. The low levels along the Mississippi River have caused restrictions in barge traffic since early Spring 2000.

Other interesting impacts in Louisiana include high prices and reduced availability of crawfish - a real problem for many connoisseurs - and a significant increase in the mosquito population. This latter result is counter intuitive but was explained by a naturalist at Tickfaw State Park near Springfield, LA. The mosquito requires very little water to breed - a relatively well known fact. However, other species which prey heavily on mosquito larvae need substantially more water depth to survive - less predation, more mosquitos!

Figure 4 shows soil moisture anomalies as of October 2000. The anomaly is the greatest over Mississippi, Alabama, east Arkansas, and all Louisiana - except the northwest corner. These extremely low soil moisture conditions pose modeling difficulties for the LMRFC and a challenge for the LMRFC forecasters. Soil moisture accounting models generally are less reliable during transitions from excessive dry periods to wet cycles.

Figure 4 : Soil Moisture Anomoly - October 2000

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Figure 5 is an estimate of the rainfall needed, as of October 21, 2000, to bring the Palmer Drought Index(PDI) to near normal levels across the U.S. and indicates that more than 9 inches are needed over much of the LMRFC with some places needing over 12 inches! Long range, meteorological predictions show some relief over the next several months as slightly above average rainfall is expected over the area from November through January. The forecast excess, however, is likely to be insufficient to seriously impact the PDI, and low flow and low soil moisture conditions could prevail into the next dry season.

Figure 5 : Additional Rainfall Needed

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- Jim Coe

Quantitative Precipitation Forecasts (QPF)s have been used daily by the LMRFC since the mid 90's. The QPF process changed during the winter/spring of 2000 giving the Hydrometeorological Analysis and Support (HAS) forecaster the responsibility of producing 24 hour QPF for direct use into our hydrologic models. The complexities and uncertainties with producing 24 hour QPF for sub-basins caused the LMRFC to reevaluate the QPF process.

Starting on October 16, LMRFC began routinely using 12 hours of QPF in river forecasts instead of 24 hours of QPF. LMRFC feels this will provide a better guidance to our customers and

remove the spatial and timing uncertainties associated with QPF more than 12 hours in the future. We will continue to process QPF for the next 24 hours and post the information to the LMRFC home page. The QPF will also be provided to the Weather Forecast Office (WFO) through the AWIPS system.

QPF will continue to be processed every 12 hours at 12z and 00z. We will update the QPF at 18z and 06z when significant rainfall is occurring or is expected. If significant changes are needed to the QPF, an update to the QPF can be modified anytime.

-Jeff Graschel