Drought - March 2009
|Contents Of This Report:||
|The weather pattern for March consisted of a series of fronts and low pressure systems which moved across the country in a generally west-to-east zonal upper-level flow. This pattern brought above-normal precipitation to parts of the Northwest and northern Plains, Midwest to Lower Great Lakes, and southern Plains to Southeast. The wet low pressure systems generally missed other areas, including the Southwest, Florida, extreme south Texas, and parts of the central Plains, Ohio Valley, and the Northeast. As a result, drought conditions improved in California and the Southeast, deteriorated over south Texas and much of Florida, and crept into parts of the mid-Atlantic region (March 31 USDM versus February 24 USDM).|
|March was drier than
normal across the western portion of Puerto
Rico, with a mixed precipitation pattern for the last
90 days and drier-than-normal conditions across the south
central and eastern portions for the last
180 days. The precipitation pattern was mixed across the
Hawaiian Islands for March,
last 6 months, and the
last 12 months, but mostly drier than normal for the
last 90 days. The precipitation pattern for Alaska was
generally mixed for March,
last 90 days,
last 6 months, and
last 12 months. But abundant precipitation fell at many
stations and April 1st
snowpack was mostly average or above.
By the end of March, the core drought areas included:
conditions, as estimated by NASA's Mosaic model (surface
deeper layers) and the NOAA Climate
Prediction Center, improved in the Southeast and parts of
Texas, but worsened in Florida and the Northeast, compared to a
month ago. Streamflow levels (both modeled
increased in the Northwest, Southeast, and parts of the southern
Plains, but decreased across parts of Florida and the Northeast
when compared to a month ago (modeled,
Data from the USGS
network of wells indicated
lingering groundwater impacts across the Southeast and
worsening groundwater conditions across parts of Florida and the
Northeast. The impact of drought on vegetation
is normally reduced this time of year due to seasonally colder
weather, but the satellite-based Vegetation Health
Index indicated stress to vegetation in the southern
The low streams and declining groundwater levels resulting from the dry weather in the Mid-Atlantic during 2009, especially in March, prompted the USGS to issue a news release warning that some shallow domestic wells may be unable to supply sufficient water to meet summer demands.
|The dryness in March was a continuation of prolonged dryness in some parts of the country. In the Northeast and mid-Atlantic states, the first three months of 2009 were dry, but the latter months of 2008 were wet. The March wetness in the Southeast and southern Plains interrupted a dry spell which can be traced back several months, while in parts of the West, dry conditions can be traced back 12 months or longer.|
|Several states had the driest January-March on record (Delaware, Maryland, New Jersey) or ranked in the top ten driest for the year-to-date (Arizona, Connecticut, New York, Pennsylvania, Utah, West Virginia). The Northeast region, as a whole, had the driest January-March on record, and for the contiguous U.S., 2009 had the third driest January-March in the 1895-2009 record.|
precipitation fell across parts of the West during February
relief and improved snowpack (April 1
versus March 1;
change map) to some areas. But long-term
deficits remained across much of the West (last 6 months,
24 months). In spite of the recent rain and snow, California
still had the sixth
driest April-March period on record.
Snowpack and snow water content remained below average across parts of the West. Reservoir levels were above average in Arizona, Colorado, and Washington, but below average across many other states. According to the Palmer Drought Index, about 52 percent of the region was in moderate to extreme drought at the end of the month, while the USDM estimated the statistics at about 28 percent in moderate to exceptional drought and about 68 percent experiencing abnormally dry to exceptional drought conditions. The differences between the Palmer and USDM statistics are due to the extreme seasonality of precipitation in the West and other hydrologic components in the drought calculations.
|A more detailed drought discussion, provided by the NOAA Regional Climate Centers and others, can be found below.|
According to the Southeast Regional Climate Center, precipitation totals for March were quite variable across the region. Precipitation was less than 50 percent of normal across much of central and southern Florida, portions of South Carolina, southeastern North Carolina and northern Virginia. Naples, Florida recorded only 0.28 inch (7 mm) of precipitation for the month, making it the 13th driest March in a record extending back 64 years. Most of Puerto Rico experienced above-normal precipitation totals for the month. The extreme drought (D3) conditions, which had persisted across extreme northeast Georgia and northwest South Carolina, were reduced to severe drought (D2) as a result of three significant precipitation events during the month. This marked the first time in two years in which the entire southeastern region was free of extreme (D3) and exceptional (D4) drought. Severe drought (D2) conditions persisted across portions of central and southern Florida. Moderate drought conditions continued across northern Virginia, western North Carolina, eastern Georgia, and portions of Florida.
As noted by the Southern Regional Climate Center, much of the southern half of the Southern Region experienced near-to-above-normal precipitation totals, in contrast to the previous two months. Northern and southern Texas observed precipitation totals that fell well below the normal range. In the northern Texas panhandle, most stations only reported approximately 25 to 50 percent of normal precipitation. It was slightly drier in the southernmost regions of the state, with many stations reporting only 5 to 50 percent of normal rainfall. Similar totals were also observed in the northern counties of the western Texas panhandle, and in the south central counties of Oklahoma.
The spatially variable pattern of March precipitation had both a positive and negative impact on drought conditions within the Southern Region. Steady and above-normal precipitation in Louisiana and southern Mississippi helped eradicate the moderate drought and abnormally dry conditions that existed in February. Similarly, near-normal precipitation in south central Tennessee led to the removal of abnormally dry conditions. In Oklahoma, dry conditions in the western counties resulted in a one category deterioration from moderate to severe drought. In addition, the two panhandles of Texas also observed a one category deterioration to moderate drought conditions. This was also the case in the southernmost counties of the state, where precipitation totals were well below normal for the month. Although many portions of central Texas observed above-normal rainfall during March, it was not sufficient to provide much improvement to the drought conditions that have persisted there for approximately one year.
As noted in the March 29 USDA Crop Weather reports, 63 percent of wheat, 70 percent of oats, 38 percent of sorghum, and 62 percent of the range and pasture in Texas were in very poor to poor condition. In Oklahoma, the ratings were 36 percent for winter wheat, 42 percent for rye, 55 percent for oats, and 33 percent for pasture and rangeland.
Texas: According to Texas AgriLife Extension Service economists, the ongoing drought in the Lone Star State has cost the state's farmers and ranchers nearly $1 billion, and losses could continue to mount this spring if sufficient rainfall isn't received for forage or row crops. Mid-March rainfall over much of Texas was too little too late as ongoing drought has cost livestock producers $569 million since November. Cattle producers spent substantial amounts on hay and supplemental feed, according to agriculture officials, and the drought losses also include failed wheat crops usually used for grazing. When totaling losses already sustained since November, AgriLife Extension economists said the ongoing drought has cost Texas $829 million to date. Those losses will likely surpass the $1 billion mark in the next 60 days as livestock producers continue to make supplemental feed purchases or sell cattle and calves in a declining market, said Dr. David Anderson, AgriLife Extension livestock marketing economist (AgNews, 3/13/09).
As explained by the Midwest Regional Climate Center, above-normal precipitation was observed across parts of the region. Below-normal precipitation fell from southeast Missouri to the southern two-thirds of Ohio and also from northwest Iowa to northern Michigan. Drought conditions continued in southeast Minnesota, northern Wisconsin, and the Upper Peninsula of Michigan while abnormally dry conditions emerged in southern Ohio.
As noted by the High Plains Regional Climate Center, precipitation was variable across the region, with the big story this month being record precipitation coupled with warm temperatures resulting in record-breaking flooding along the Red River in eastern North Dakota.
Kansas: As described by the Kansas Water Office, March precipitation totals varied widely across the state with eastern and south central areas generally running well above normal while northwest and north central areas were much drier than usual. Several locations reported no precipitation during the month. Total precipitation was less than 50 percent of normal across most of western Kansas since January 1st, with a large area receiving less than 25 percent of normal. Long-term persistent dryness in southwest Kansas was evident at the 12-month timescale as were wetter-than-normal areas in north central and southeast Kansas.
The March 30 Kansas Crop and Weather Report rated statewide topsoil moisture as 35 percent short-very short compared with 66 percent short-very short one month ago and 22 percent short-very short at this time last year. The northwest and west central districts, which missed the brunt of a March 27th storm, both reported topsoil moisture as 88 percent short-very short. Subsoil moisture was rated 29 percent short-very short, 64 percent adequate and 7 percent surplus, statewide. Twenty-two large wildfires have been reported to the Kansas Forest Service from 12 Kansas counties so far this year. These fires burned a total of 21,600 acres. Five fires were over 1,000 acres in size.
Moderate or severe drought conditions were indicated at month's end by the U.S. Drought Monitor in all or most of seven southwest or south central Kansas counties adjacent to the Oklahoma border. Abnormally dry conditions covered the remainder of western Kansas. This represented some reduction in the area covered by abnormally dry or drought conditions compared with the situation one month ago, except for severe drought, which was not previously indicated. No county drought declarations were presently in effect and no drought-related public water system impacts were currently being reported. But, at the request of Governor Kathleen Sebelius, U.S. Secretary of Agriculture Tom Vilsack designated Scott County as a primary disaster area on March 30th. This designation was based upon crop production losses due to drought and high winds between January 1 and December 31, 2008.
As summarized by the Western Regional Climate Center, except for northern Idaho, western Montana and portions of Wyoming, most of the West had a drier-than-normal March. Although a strong storm hit California during the first four days of the month producing heavy rain and snow, most locations had monthly totals well below average. An important exception was the northern Sierra, which had precipitation and snowfall totals of up to 115 percent of normal, increasing the snowpack from 70 percent of normal at the beginning of the month to 80 percent by the end of the month. The Eight-Station Index used for tracking input to the California State Water Project ended the month at 8.2 inches (208 mm), 119 percent of average. Except for the Southwest, the rest of the West was near or slightly above normal on the April 1st snow surveys. Although the Southwest was extremely dry, Albuquerque measured 0.24 inch (6.1 mm) on the 9th, breaking a 72-day string of no-precipitation days, their eighth longest such spell. Seattle continued with their unusually snowy winter and up until March 26th had measured more snowfall for the winter season (20.3 inches; 51.3 cm) than Denver's 19.1 inches (49.0 cm). Nome, Alaska, recorded their snowiest March on record, which followed their snowiest February on record. This led to the second greatest snow depth ever recorded, 78 inches on the 12th.
California: As noted by the California State Climatologist, a March 30, 2009 drought report from the California Department of Water Resources to the Governor's office provided an update on the state's drought conditions and water availability. The report states that, "while there have been some improvements in this year's hydrologic conditions, allocations to state and federal water contractors are expected to remain at or near record lows for the rest of 2009. As a result, many parts of California will be faced with reduced water supplies this year." The report notes that responding to conditions this year and preparing for possible future dry years are critically important to meet statewide water needs. Over the last two months, the state's reservoirs gained nearly 3 million acre-feet of storage. Smaller reservoirs like Friant and Folsom were able to fill to their current flood control limits. However, the state's largest reservoirs (Lake Shasta and Lake Oroville), which are major water supply sources for the state and federal water systems, still remained significantly below average. The drought has caused economic hardship in California, particularly in agricultural communities.
As noted by the Northeast Regional Climate Center, on average, the Northeast received below-normal precipitation in March. Central and western New York and northeast Pennsylvania were the only regions with above normal precipitation. Central and southern Pennsylvania, most of New Jersey, and portions of Maryland were the driest in the Northeast, receiving only 25 to 50 percent of their normal March precipitation totals.
Drought conditions expanded to the north during March. The U.S. Drought Monitor issued March 31, 2009 indicated that the southern half of Pennsylvania and all of New Jersey and Delaware were abnormally dry. In West Virginia, most of the state was experiencing abnormally dry conditions. The exceptions were portions of the Central, Southern and Northeastern climate divisions, which were in the moderate drought category. Moderate drought conditions were also found in most of central Maryland, with abnormally dry conditions in the rest of the state.
|A detailed review of
drought and moisture conditions is available for all contiguous U.S.
states, the nine standard regions, and
the nation (contiguous U.S.):