Monday, May 21, 2018

National Drought Mitigation Center

Drought and Climate for April 2018: Conditions worsen in southern High Plains, Desert Southwest

Access the latest monthly drought outlook from NOAA's Climate Prediction Center.
 
The two maps above are from the High Plains Regional Climate Center.
 
Find these and other products related to the U.S. Drought Monitor on the USDM website.

By Curtis Riganti, NDMC Climatologist

Drought

During April, drought expanded and worsened over much of the southern High Plains and Desert Southwest, while conditions improved in parts of coastal Georgia and South Carolina. Exceptional drought was introduced over the Four Corners and expanded into parts of northeast New Mexico and the Texas Panhandle. Moreover, extreme drought expanded in parts of Arizona, New Mexico, Colorado, and Texas. Overall, moderate drought coverage decreased from 29.42 to 28.6 percent, severe drought coverage slightly decreased from 16.37 to 16.32 percent, extreme drought coverage increased from 7.59 to 8.89 percent, and exceptional drought coverage increased from 0.6 to 2.2 percent.

Drought Outlook

During May, drought is expected to persist in the southern and central Plains and Desert Southwest, and to slightly expand in southeast Oregon. On the northern and eastern periphery of the Plains and Southwest drought areas, improvement or removal of drought is expected to take place.

Temperatures

During April, the Upper Midwest, northern Plains, and middle and lower Missouri River valleys experienced below-normal temperatures. Compared to normal, the coolest conditions were found in Minnesota, the Dakotas, and Wisconsin, where April temperatures fell 9-15 degrees below normal. Aside from the Florida Peninsula, generally cooler than normal conditions enveloped the central and eastern two-thirds of the continental United States. Meanwhile, the warmest conditions took place in the Southwest, where temperatures were 3-9 degrees above normal.  

Precipitation

Dry conditions continued in the Desert Southwest as the region continues to transition to their dry season. The driest conditions (compared to normal) occurred in the middle and lower Missouri River Valley, where many areas saw less than 50 percent of their normal April precipitation. Similarly dry conditions occurred in north-central Minnesota and north-central and northeastern North Dakota. Much of western Washington and northern California received above-normal precipitation during April, as did the Jacksonville, Florida, area.

Regional Overviews

Northeast

April precipitation in the Northeast was variable; southwestern and central Pennsylvania, northern Vermont, northern New Hampshire, northern and southeastern Maine, and northern West Virginia received near- or above-normal precipitation, while Long Island, central New York, and southern New Jersey received below-normal precipitation. Northern Vermont, northeastern New York, northern New Hampshire, and southwestern Pennsylvania received 130-300 percent of normal precipitation for the month. Cooler than normal conditions prevailed in the Northeast in April, with the coolest conditions (from 4 to 8 degrees below normal) taking place in the eastern Great Lakes region and northwestern New England. At the beginning of the month, 0.12 percent of the Northeast was in moderate drought (a small area of southwest Maryland); this drought was removed by the end of April.

Southeast

Most areas of the Southeast received normal or above-normal precipitation during April, though a few areas were also drier. The most notable dry areas were the western Florida Panhandle, southeastern Alabama, parts of the southern Florida Peninsula, and parts of southeastern Virginia. Near normal and warmer than normal conditions occurred in the Florida Peninsula, where some spots saw temperatures 2-6 degrees above normal. Elsewhere, temperatures were near normal or cooler than normal. The coolest temperatures took place in the Appalachian regions of Georgia, North Carolina, and Virginia, where some areas saw temperatures 2-6 degrees below normal. During April, drought coverage was reduced in Georgia and Alabama; moderate drought coverage dropped from 26.31 to 14.26 percent, and severe drought coverage was reduced from 6.68 to 2.35 percent.

Movers & Shakers for April 2018
State

Percent area April 3, 2018

Percent area May 1, 2018 Status Percentage point change
Biggest increases in drought
Alabama 18.90 2.64 Moderate 16.26
California 40.90 37.10 Moderate 3.80
Iowa 7.61 14.18 Moderate 6.57
Kansas 81.66 84.88 Moderate 3.22
56.19 59.47 Severe 3.28
Missouri 9.14 16.54 Moderate 7.40
Nevada 12.78 31.03 Moderate 18.25
New Mexico 38.87 45.06 Extreme 6.19
0 10.59 Exceptional 10.59
Oklahoma 15.11 23.93 Exceptional 8.82
Oregon 32.89 39.92 Moderate 7.03
Texas 21.57 25.50 Severe 3.93
Utah 21.05 27.80 Extreme 6.75
0 3.74 Exceptional 3.74
Biggest improvements in drought
Alabama 18.90 2.64 Moderate 16.26
California 40.90 37.10 Moderate 3.80
Colorado 73.67 67.98 Moderate 5.69
Florida 25.71 22.23 Moderate 3.48
Georgia 51.19 28.48 Moderate 22.71
16.00 5.30 Severe 10.70
North Dakota 42.03 39.01 Moderate 3.02
South Carolina 51.47 23.91 Moderate 27.56
24.05 0 Severe 24.05
South Dakota 32.48 19.26 Moderate 13.22
12.01 0 Severe 12.01

South

Dry conditions continued in the southern Plains and southern High Plains of Texas and Oklahoma, while near-normal or slightly wet conditions were found in most of Arkansas, Mississippi, Tennessee, and Louisiana. Particularly dry conditions were found from central and northern Texas into the southern Texas Panhandle. Temperatures across the South were generally below normal or near normal. The coolest regions (where temperatures varied from 2 to 8 degrees below normal) were central and eastern Oklahoma, northeastern Texas, Arkansas, northern Mississippi, and western Tennessee. In southwestern Texas, temperatures varied from near normal to 4-6 degrees warmer than normal for April. The southern Plains drought degraded in western Oklahoma, the eastern Texas Panhandle, and the Edwards Plateau, while conditions improved slightly in parts of the western Texas Panhandle, central Texas, and the Lower Rio Grande Valley.

Midwest

Two primary dry regions covered the Midwest during April. The northwestern two-thirds of Missouri, southern Iowa, northern Illinois, northwestern Indiana, southern Wisconsin, northwestern Wisconsin, and northern Minnesota received generally 70 percent or less of their normal April precipitation, with northern Missouri, southern Iowa, and northern Minnesota receiving mostly less than 25 percent of normal. Normal and wetter than normal conditions occurred in a strip from northwestern Iowa through Door County, Wisconsin, to northern and southeastern Lower Michigan. April temperatures in the Midwest were 4-16 degrees cooler than normal. The coolest conditions took place in Iowa, Minnesota, Wisconsin, and northern Michigan. Moderate drought coverage increased in southern Iowa and northwestern and north-central Missouri, bringing the regional moderate drought coverage from 2.37 to 4.15 percent.

High Plains

During April, precipitation anomalies varied across the High Plains region, with most areas receiving below-normal precipitation for the month. The driest conditions were in central and eastern Nebraska, south-central and southwestern Colorado, much of North Dakota, and eastern Wyoming, where some areas saw less than 25 percent of their normal April precipitation. The region was generally cooler than normal for April, with the exception of areas in and west of the Rocky Mountains in Colorado and Wyoming. Temperatures in eastern Nebraska, central and eastern South Dakota, and North Dakota fell to as far as 15 degrees cooler than normal for the month. Meanwhile, temperatures in south-central and southwestern Colorado were generally 3-6 degrees above normal for April. Moderate drought coverage dropped from 39.79 to 36.76 percent. Severe drought was removed from South Dakota and added in north-central North Dakota; coverage across the region decreased slightly, from 22.09 to 21.06 percent. Extreme drought was expanded over southern Colorado and southwestern Kansas, increasing the regional coverage from 8.97 to 10.7 percent. Exceptional drought was introduced in southwestern Colorado and the San Luis Valley and was slightly expanded in south-central Kansas, increasing the regional coverage from 0.7 to 2.19 percent.

West

Precipitation in the West during April was mostly above normal in northern California, western Oregon, Washington, and northern Idaho, while below-normal precipitation occurred in southern California, most of New Mexico, parts of south-central Utah, and parts of southwestern Idaho and northeastern Nevada. The wettest conditions occurred in western Washington, where precipitation was 150-300 percent of normal. Warmer than normal temperatures covered much of interior California, Nevada, Utah, Arizona, and central and western New Mexico. The warmest areas of these states saw temperatures 6-8 degrees above normal. Meanwhile, Montana experienced cooler than normal temperatures, with the coolest temperatures (6-12 degrees below normal) taking place in the high plains of Montana. During April, moderate drought coverage increased slightly from 43.02 to 43.89 percent, severe drought coverage increased slightly from 27.63 to 28.3 percent, extreme drought coverage increased from 12.46 to 15.5 percent, and exceptional drought was introduced in the Four Corners, northeastern New Mexico, and the San Luis Valley and covered 2.72 percent of the West at the end of April.

 


 

April 2018 impact summary: Producers deal with parched pastures and crops in southern U.S.

The two charts above summarize information from the Drought Impact Reporter.

By Denise Gutzmer, NDMC Drought Impact Specialist

Drought intensified in parts of the southern Plains and the Southwest in April, while conditions eased in the northern Plains and the Southeast.  Wheat continued to struggle in need of moisture in the southern Plains, while ranchers sent livestock to feedlots, given the parched pastures.  Many of the 126 impacts added to the Drought Impact Reporter in April noted signs of drought among plants and wildlife, as well as agriculture.  Texas had 32 impacts, with New Mexico and Arizona following with 26 and 20 impacts, respectively. 

Extreme wildfire weather noted in southern Plains and Southwest

Strong, gusty winds and very low humidity in drought-affected areas combined to create extremely hazardous fire conditions in parts of the Southwest and southern Plains, leading a forestry official to characterize April 17 as being historically critical.  Oklahoma, in particular, experienced some massive wildfires that blackened hundreds of square miles before containment.  Two of the state’s largest wildfires were the Rhea Fire, which burned 286,196 acres, or 447 square miles, in Dewey County, and the 34 Complex Fire, which burned 62,432 acres, or 97 square miles, in Woodward County. 

After the flames died down, cattle ranchers in Colorado, Kansas, Oklahoma, Texas and New Mexico were hard-pressed to find hay or pastureland because of the ongoing drought and numerous wildfires. Some ranchers were even resorting to selling livestock.

Forecasters warn of rare, life-threatening wildfire weather, by Ken Miller, Associated Press, The Pueblo Chieftain (Colorado), April 17, 2018

Rhea Fire at https://inciweb.nwcg.gov/incident/5746/

34 Complex Fire at https://inciweb.nwcg.gov/incident/5747/

Drought, wildfires force ranchers to scramble for feed, by Ken Miller, Associated Press, NewsOK.com (Oklahoma City), April 24, 2018

Drought affecting Texas agriculture

The western half of Texas has dealt with various levels of drought, affecting livestock, crops and water supplies.  Farmers in the Panhandle, the worst affected area in the state, dealt with poor winter wheat conditions, inability to plant summer crops for the dryness, and dormant rangelands.  Many producers reevaluated stocking rates, as most rangelands and pastures west of the Pecos River had not received significant rain since October 2017. 

On April 13, Governor Greg Abbot announced a state disaster declaration for more than 70 Texas counties enduring intense drought and an increased fire danger amid the wildfire outbreak. Per the governor’s office, the drought conditions created an imminent threat to public health, property and the economy.

Texas Crop and Weather Report – April 10, 2018, by Adam Russell, The Bryan-College Station Eagle (Texas), April 10, 2018

Texas Crop and Weather Report - April 17, 2018, by Adam Russell, North Texas e-News (Fannin, Texas), April 18, 2018

Gov. Abbot issues State of Disaster Declaration for Texas counties experiencing drought, by Matthew Watkins, KVII-TV ABC 7 Amarillo (Texas), April 13, 2018

Low streamflows noted in New Mexico

Poor snowfall during New Mexico’s winter left the April to June streamflow forecast low for many parts of the state.  Flows were unusually low on the Rio Grande River, prompting biologists to begin rescue efforts on April 2 to salvage the Rio Grande silvery minnow, a tiny fish listed as endangered since 1994. More than 10 miles of the Rio Grande River in the vicinity of Bosque del Apache National Wildlife Refuge were dry, making this one of the earliest salvage efforts. The fish were taken upstream to wetter stretches of the river and released.

Drought and heat also increased the fire risk in the region and led many counties, national forests and ranger districts to issue fire restrictions earlier in the year than normal.  Santa Fe National Forest and the Mountainair and Sandia ranger districts were some of the areas with fire restrictions, as were Bernalillo, Colfax, Lincoln and Curry counties.

Rio Ruidoso may see 25 percent of average flow this spring, by Dianne L. Stallings, Ruidoso News (New Mexico), April 10, 2018

Minnow rescues under way as portions of Rio Grande dry up, by The Associated Press, Valley Morning Star (Harlingen, Texas), April 13, 2018

Fire restrictions implemented around New Mexico, by Marian Camacho, KOB 4 (Albuquerque, New Mexico), April 11, 2018

The Latest: New Mexico Counties Impose Burn Bans, by The Associated Press, U.S. News & World Report (Washington, D.C.), April 11, 2018

Streamflows very low in Arizona

The 2017-18 winter in Arizona was the driest in recorded history, according to the Arizona Department of Water Resources.  The total watershed streamflow this season was forecast to be near the lowest runoff on record, which was 106,000 acre-feet in 2002. 

Amid the dry winter and spring and early heat, the Tonto and Prescott national forests implemented fire restrictions on April 18 and April 20, respectively, earlier in the season than usual.  Days later, the Arizona Department of Forestry announced fire restrictions for the southern part of the state beginning May 1 as drought worsened.  The fire restrictions mean campfires, barbecues and wood stoves are prohibited even within developed recreation sites for many national forests, parks and monuments in the southern part of Arizona. 

Driest winter ever recorded for Arizona’s mountain watersheds, by Jeff Beamish, KVOA-TV NBC 4 Tucson (Arizona), April 18, 2018

Fire restrictions begin on Tonto and Prescott National Forests, Timothy Johns, KASW-CW6 & KTVK-3TV (AzFamily.com), April 13, 2018

Fire restrictions coming to southern Arizona, by Jeff Beamish, KVOA-TV NBC 4 Tucson (Arizona), April 24, 2018

Poor snowpack and water supplies spur water restrictions in Colorado

Poor snowpack in Colorado led some cities to begin water restrictions in anticipation of lower than normal water supplies for the rest of the year.  Steamboat Springs and Ridgway both enacted restrictions in the last week of April.  Denver Water officials opted to get more water from the northern mountains in response to poor snowpack in the upper South Platte River Basin.  Statewide, Colorado’s snowpack was 66 percent of normal on April 5.

Restrictions begin Tuesday to conserve water in Steamboat Springs area, by Matt Stensland, Steamboat Pilot & Today (Colorado), April 24, 2018

Town announces voluntary outdoor water restrictions, by Justin Criado, Telluride Daily Planet (Colorado), April 26, 2018

Mountain snowpack shrinks to 66 percent of normal, feds sound drought alarm, by Bruce Finley, The Denver Post, April 5, 2018

 

For more drought information, please visit the Drought Impact Reporter.

 

 

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