For all but the southern states, it was another mild weather week as drought conditions continued across much of the west, north and east. A broad expansion of dry conditions is depicted over much of the West, from Idaho to Colorado to California. Improvements are seen in Texas and some nearby states as a system late in the week brought some heavy precipitation over a two-day period.
The West: Continued dry conditions are prompting introduction of Moderate drought in the central plains of Washington and northern Oregon. Seasonal precipitation totals are dismal, with 50 percent or less of normal for the last 90 days. Very little snowfall all across the western states is causing further degradation in the Sierra Nevada to short-term Severe Drought, as impacts to forage conditions in rangeland areas are significant. Wildland fire awareness is increasing in California as well. A large area of D0, Abnormally Dry, was expanded over San Bernardino county, California, and Clark county, Nevada. Bartow-Daggett area of California had its 10th driest year on record in 2011, and Las Vegas and Mt. Charleston, NV both ranked in the top 15 driest on record.
In the Great Basin and headwaters of the Colorado River, D0 is introduced this week to reflect lack of snowfall thus far in the typically wet season. Ski resorts are suffering due to warm and dry conditions, even though water supply reservoirs continue to hold storage from the last wet year.
In the southwestern states, an impact line was drawn to separate the short-term and long-term nature of drought between the northern and southern states.
Northern Plains and Midwest: Record high temperatures in the 60s in South Dakota, Nebraska, and nearby areas were reported on January 5. The warm streak continued over the weekend, and snowfall remained absent. An expansion of Abnormally Dry conditions is shown in western South Dakota, near Wessington Springs, SD in the east, and in southeastern Nebraska. Warm temperatures have increased natural water demand on the top soil layers, resulting in reports of topsoil dryness although there is moisture found deeper in the soil. The mild temperatures have not had much effect on winter wheat, but have led to reduced hardiness in woody vegetation to survive the winter.
Southern and Central Plains: A couple of strong systems plowed through Texas, Oklahoma and Louisiana to bring relief during this U.S. Drought Monitor period. One-category improvements were made across much of Texas, and impact lines were shifted to better reflect the short- and long-term nature of drought in the state. Snowfall totals upwards of more than ten inches were reported in panhandle region of Texas. As much as three or more inches of rain fell along the Gulf coast from Galveston, TX to Lake Charles, LA, over a two-day period earlier this week. This warranted removal of Exceptional drought in southwestern Louisiana, and one-category improvements are depicted in this broad area. Low reservoir levels and other impacts remain, however, and an Extreme Drought situation continues.
One area of worsening conditions is shown in Osage county in northeastern Oklahoma, as a result of slow reservoir response to recent precipitation in the area.
The Southeast and Mid-Atlantic: Drought continues its hold on the Southeastern states, as Moderate drought reaches further into Florida this week. The Gulf coast around Tampa and the northern counties around Gainesville are experiencing significant shortages of precipitation for this time of year. Gainesville has recorded their third driest 365 day period on record, with a mere 32.40 inches of rain. In South Carolina, a one-category degradation to D2 and D3 was made from south central South Carolina to the coast. North Carolina remains wet in the west and dry in the east, as Abnormally Dry conditions are expanding to the central and northern reaches of the state, and further north into Virginia and the Delmarva peninsula. Widespread development of dry conditions are becoming apparent in the region.
Alaska, Hawaii and Puerto Rico: No changes were made in Alaska, as they are experiencing heavy snow across much of the state this winter. Record snowfalls over the last couple of weeks have staved off the development of any dry conditions.
In Hawaii, an expansion of D0 is depicted this week on the southwestern slopes of Kauai.
There are no changes made to the map of Puerto Rico.
Looking Ahead: A wetter pattern is welcome in the northern states where the lack of rain and snow has begun to take its toll. For the next U.S. Drought Monitor period, the outlooks show a potential for above normal precipitation in the northern states, from the Pacific Northwest to the Great Lakes and Midwest. Below normal precipitation for the week is forecast in the southern states, primarily from Arizona to Texas and north to Nebraska, and across the southern tip of Florida. This could exacerbate, or at least maintain, much of the drought in that region. Temperatures from Washington state to Michigan are projected to be below normal. Warmer than average conditions will likely prevail across much of the rest of the nation, from Nevada to Maine and southward to the Gulf coast. Alaska will be colder than normal over the next several days, with below normal precipitation likely.
D0 ... Abnormally Dry ... used for areas showing dryness but not yet in drought, or for areas recovering from drought.
Drought Intensity Categories
D1 ... Moderate Drought
D2 ... Severe Drought
D3 ... Extreme Drought
D4 ... Exceptional Drought
Drought or Dryness Types
S ... Short-Term, typically <6 months (e.g. agricultural, grasslands)
L ... Long-Term, typically >6 months (e.g. hydrology, ecology)