California and National Drought Summary for March 7, 2017

Summary

March 9, 2017 - Active weather across the Midwest during the beginning and end of the current period brought rain and severe storms over the region. Warm and windy conditions dominated conditions on the Plains; wildfires were a great concern throughout Oklahoma and Kansas, with multiple fatalities associated with the fires. Temperatures from South Dakota into Texas were 6-9 degrees above normal, with portions of eastern Nebraska and eastern Kansas 9-12 degrees above normal. Much of the West was cooler than normal with departures of 3-6 degrees below normal. Rain and snow over parts of northern California and into the coastal regions of Oregon and Washington continued the active pattern that has been consistent over the West Coast. The driest areas of the Southeast did pick up some precipitation, but most areas were normal to slightly below normal for the week.

The Northeast and Mid-Atlantic

The impact of the recent precipitation over the last several weeks allowed for the extreme drought conditions to be removed from Connecticut this week. Long-term conditions are still very dry, but the region has seen a response from the impact of melting snow and rain, which allowed for the improvements to be made. No other changes were made this week, but the Mid-Atlantic will need to be watched for worsening conditions if the dryness continues.

Southeast

Warmer than normal conditions dominated the region, with departures of 3-6 degrees above normal common throughout the region. Most of the region was drier than normal for the week, with the Florida peninsula being one of the driest areas. Not many changes were made this week. Abnormally dry conditions were introduced in portions of southern North Carolina into northern South Carolina. Over northern Alabama, severe drought conditions were improved to moderate drought as 2-3 inches of rain centered over Morgan County at the end of the week allowed for improvements. Over the last 30-60 days, the drought indicators are showing a rapid decline, and without additional rain, drought conditions are likely to expand and intensify in the region, especially as water demand increases as the transition to spring takes place.

Midwest

It was a fairly wet week over much of the Midwest with several frontal passages responsible for rain and thunderstorms. The area from southern Illinois into western Pennsylvania recorded the most rain, with some areas recording up to 3 inches. With the recent rains, abnormally dry conditions were removed over much of Indiana and portions of eastern Illinois and northern Kentucky. Areas of Missouri, Iowa, and Illinois remain dry over multiple timescales. Severe drought was introduced over central Missouri while moderate drought was expanded from northern Missouri into southern Iowa and more of western Illinois.

High Plains

A warm, windy, and dry week dominated the High Plains, with only scattered rain over the region. Conditions are drying out with the windy and warm weather and any moisture recently received has been evaporated quite rapidly. Abnormally dry conditions were expanded over southeast Nebraska and into eastern Kansas while moderate drought was expanded over eastern Kansas as well. In southwest and south-central Kansas, moderate and severe drought were expanded slightly this week too. This area will need to be monitored closely for further degradation if precipitation does not materialize.

South

Rains over southern Texas allowed for improvements to moderate drought and abnormally dry conditions. In northeast Texas and southern Louisiana, dry conditions allowed for the expansion of abnormally dry conditions as well as a slight expansion of moderate and severe drought along the Texas and Oklahoma borders. Over the last several weeks, impacts to agriculture and rangeland over Oklahoma due to drought increased quickly. Several deadly wildfires also brought hardships to the region. Any moisture in western Oklahoma was quickly evaporated with the warm and windy conditions. In response to the changing conditions, a new area of extreme drought was introduced into the panhandle of Oklahoma, with moderate and severe drought expanding as well in both the Oklahoma and Texas panhandles. Severe drought was expanded over northern and eastern Oklahoma too.

West

Cooler than normal conditions dominated the West, with precipitation over the coastal regions and into the Southwest. Several improvements were made this week in response to not only recent precipitation but also precipitation over the last several months. In Montana, good snow totals allowed for some improvement to the abnormally dry conditions. Abnormally dry conditions were removed from eastern Oregon due to the short-term indicators improving the overall conditions and superseding the long-term indicators. In southern California, severe drought was eliminated in the Santa Barbara, Ventura, and Los Angeles county region as the response from recent rains has improved long-term impacts to groundwater. Improvements were also made in the Imperial Valley in response to recent rains where abnormally dry, moderate drought and severe drought were all improved. In Arizona, abnormally dry conditions were improved over the eastern portion of the state as well as the central portion of the state. Some abnormally dry conditions were left in place because of the low snow totals from this current water year.

Hawaii, Alaska and Puerto Rico

Abnormally dry conditions were removed from Maui this week while they expanded over the Big Island on Hawaii. Status quo was maintained for Alaska and Puerto Rico this week.

Looking Ahead

Over the next 5-7 days an active pattern will develop over the South and into portions of the Southeast. Up to 2 inches of rain is projected from south Texas into portions of Louisiana and Mississippi. Another storm system will impact the Pacific Northwest with both coastal and inland regions anticipating over 4 inches of rain and snow accumulating in the upper elevations. Cooler air will move south out of Canada, bringing with it colder than normal temperatures over the eastern half of the United States. Warmer than normal temperatures are expected over much of the West and Southwest, with departures of up to 12 degrees above normal.

The 6-10 day outlooks show a high probability of above-normal temperatures centered over the Southwest and impacting most areas from the West, Plains, and Southeast. A higher probability of cooler than normal temperatures is anticipated over Alaska, New England and the Pacific Northwest. The highest probabilities of above-normal precipitation are projected to be over the Pacific Northwest and New England while both the Plains and Alaska are showing the highest chances of below-normal precipitation.

Author(s):
Brian Fuchs, National Drought Mitigation Center

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Dryness Categories

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)
Source: National Drought Mitigation Center