Subsection of National Drought Monitor for June 19. Yellow indicates abnormally dry areas, tan indicates moderate drought, brown indicates severe drought, and red indicates extreme drought.  (See full U.S. map.)	Subsection of National Seasonal Drought Outlook indicating areas in brown where drought is expected to persist or intensify during the period from June 21 to September 30.  The arrow points to the area (yellow) where drought is likely to develop during this period.  (See full U.S. map.)
For weekly updates to these and related resources, visit the U.S. Drought Monitor and the National Drought Mitigation Center.

June 22, 2012

For July, Expect Above Normal Temperatures and Below Normal Precipitation

Blistering heat invaded western Nebraska June 17-19, with highs exceeding 100°F across portions of the Panhandle, southwest, and west central Nebraska. On June 18 McCook reached 109°F, the warmest temperature recorded in the state this year. Wind speeds were consistently in the 20-30 mph range, with gusts over 40 mph. Along the Kansas-Nebraska border, potential evapotranspiration rates exceeded 0.50 inches per day during this period.

Unfortunately, rainfall was not as widespread as the heat. Scattered showers and thunderstorms dropped pockets of rain across the state during the past week, with the best coverage occurring across eastern Nebraska June 20 when a cold front pushed southeastward through the state. Isolated pockets of 0.75-1.25 inches were reported in the Columbus, Fairbury, and Omaha areas, but 0.25-0.50 inch was more commonly reported across southeast and east central Nebraska.

The exceptional heat and lack of significant moisture has resulted in a further expansion of drought conditions across western Nebraska. With the June 14 rain, conditions in south central, east central, and southeast Nebraska improved some. (It should be noted that rainfall occurring after 7 am June 19 was not included in the current U.S. Drought Monitor depiction. Localized pockets within regions classified as experiencing drought may have conditions that are better or worse than currently indicated on the map.

Pastures have declined rapidly across western Nebraska with the continuous heat and lack of moisture. Cool season grass production declined rapidly during the past two weeks and warm season grasses have not responded well to the lack of moisture. With corn quickly approaching reproduction, heat and precipitation will be critical.

Short-term weather models (less than 14 days) indicate widespread heat for western Nebraska June 24-27. Highs of 100°F or more are likely in the Panhandle, western Sandhills, and southwest Nebraska. Even if 100°F plus temperatures are not realized, temperatures in the upper 90s will be widespread. Eastern Nebraska will likely average about 5-8 degrees (F) cooler during this period.

All of this heat will be in response to an upper air ridge building over the central Plains region. Precipitation will develop along the periphery of this upper level ridge. The best moisture chances will be across extreme northern Nebraska until cooler air pushes southward during the second half of next week. During the first week of July, models hint at increasing rain chances, but ultimately the position of the central Plains high will dictate where thunderstorm activity develops.

July Forecast

The Climate Prediction Center (CPC) has issued its July forecast and it is definitely not positive regarding heat and precipitation. It indicates above normal temperatures for Nebraska in July and below normal precipitation for the eastern three-fourths of the state, with the eastern one-third having the greatest liklihood for below normal precipitation. An area of below-normal precipitation extends from eastern Nebraska east-southeast toward the southern half of the eastern Corn Belt.

Even through the CPC doesn’t assign a July precipitation trend for western Nebraska, there are no indications that an extended wet spell is on tap. In fact, the U.S. Drought Monitor authors have projected that the drought conditions will continue during the mid-June through mid-September period, with expansion likely across areas of the state currently depicted as experiencing no dryness issues.

Al Dutcher
Extension State Climatologist