April 2012 Climate Summary

For a printable version of the climate summary which includes more figures, data tables, and state summaries, click here. 

Temperature Summary

The High Plains Region was warm again this month. Similar to March, based on preliminary data, every station in the Region had above normal temperatures. Monthly temperature departures of 4.0-6.0 degrees F (1.1-3.3 degrees C) above normal were widespread across the Region and areas where temperature departures were 6.0-8.0 degrees F (3.3-4.4 degrees C) above normal included central and eastern Colorado, central and northeastern Wyoming, western South Dakota, the panhandle of Nebraska, and southeastern Kansas. The warmth caused numerous locations to be ranked in the top 10 warmest Aprils on record. Wichita, Kansas had its 5th warmest April on record with an average temperature of 62.5 degrees F (16.9 degrees C) which was 7.2 degrees F (4.0 degrees C) above normal (period of record 1888-2012). The record from 1981 and 1896 stood at 63.7 degrees F (17.6 degrees C).

The warm conditions this spring allowed for planting progress, especially of corn, to be ahead of schedule throughout the Region. Going into April, there were concerns in the southern portion of the Region about the possibility of freeze damage as the average last freeze date is around mid-April to early May. While freezing temperatures did occur, only slight freeze damage was reported. Aside from agriculture, plant development in general was ahead of schedule. In southeast Nebraska, for instance, roses and peonies were blooming about 5 weeks ahead of schedule.

Precipitation Summary

Precipitation varied across the Region this month. Much of the eastern half of the Region had precipitation totals which were higher than normal, while lower than normal precipitation areas included most of Wyoming, the western half of Colorado, central and northeastern Kansas, and isolated pockets in Nebraska and the Dakotas. Most of the above normal precipitation locations ranged from 125-200 percent of normal, but there were pockets of 200-400 percent of normal precipitation that occurred in east-central Colorado, west-central Nebraska, east-central South Dakota, and southeastern North Dakota.

Although monthly records were not broken, there were some daily precipitation records and most of these occurred in the middle and at the end of the month. The severe storms of April 14th were accompanied by heavy rainfall of 2-3 inches (51-76 mm) across portions of northern Kansas, Nebraska, and eastern South Dakota. April 30th was extremely wet in southern Kansas, near the Oklahoma border. Take, for instance, Parsons 2 NW, Kansas which received 5.35 inches (136 mm) of precipitation on that day. This one-day precipitation total was more than what Parsons usually gets in the entire month of April (normal April precipitation is 3.82 inches (97 mm)). This also completely crushed the old daily record of 2.68 inches (68 mm) which was set in 1954 (period of record 1925-2012).

Snowfall was sparse this month and due to the continued warmth, snow pack has declined in the mountainous portions of the Region. According to the Natural Resources Conservation Service, by the end of the month, the statewide snowpack was 19 percent of average in Colorado and 45 percent of average in Wyoming. The low snowpack has raised concerns about irrigation water availability for the growing season. In addition, according to the Denver Post, Independence Pass was scheduled to open two weeks ahead of schedule because of the lack of snow in the mountains. The pass usually opens the Thursday before Memorial Day weekend

Climate Outlook

La Niña conditions are currently transitioning to ENSO-neutral conditions. The temperature outlook indicates a higher probability of above normal temperatures for all of Colorado, the southern half of Wyoming, western Kansas, and western Nebraska. There is also a higher probability of below normal temperatures in the western half of North Dakota, northwestern South Dakota, and far northern Wyoming. The precipitation outlook indicates a higher probability of below normal precipitation for the majority of Wyoming and the northwestern corner of Colorado. Equal chances of above, near, or below normal precipitation and temperature are predicted elsewhere in the Region. The seasonal outlooks combine the effects of long-term trends, soil moisture, and when applicable, the El Niño Southern Oscillation cycle (ENSO).More information about these forecasts can be found here.

Drought Watch

There were many changes again to the U.S. Drought Monitor this month. The drought conditions in the areas near the Colorado-Kansas border have continued to improve as all extreme drought conditions (D3) have been erased and only a couple of small areas of severe drought conditions (D2) remain. In eastern South Dakota, D2 was downgraded to moderate drought conditions (D1) and some drought conditions were completely eliminated in the northwest portion of the state. Although recent rains have led to improvements in these areas, others have seen degradation. The small area of D2 in western Colorado has expanded to include much of the west-central portion of the state. A patch of D1 that was in western South Dakota has been extended north into North Dakota and south into the panhandle of Nebraska. Abnormally dry conditions (D0) were also expanded to include eastern Wyoming and small areas of D1 have also crept into southern portions of the state. According to the U.S. Seasonal Drought outlook released on April 19th, drought conditions were expected to improve in areas of the Dakotas and eastern Nebraska. Drought conditions elsewhere in the High Plains Region were expected to persist or develop.