May 2015 Climate Outlook: A look back and a look ahead

BROOKINGS — As South Dakota transitions from April to May, warmer than average air and soil temperatures are prevalent throughout the state. However, spring precipitation has failed to appear across most of the state creating winter wheat and forage issues, explained Dennis Todey, SDSU Extension Climate Specialist & South Dakota State Climatologist.

“Lack of precipitation has led to a number of agricultural issues,” said Todey. “If we don’t receive adequate moisture in May, the issues could increase.

To clearly explain the climate outlook, Todey begins by taking a look back at the year-to-date conditions.

A look back

April was very dry across most of South Dakota, with only a few weather locations to the west recording slightly above average precipitation. Total precipitation across the state ranged from 0.11-inches to just over 2-inches. The largest deficits were in the southeast where April was 2 inches or more below average, Todey said, referencing precipitation totals in Chamberlain, 0.41 inches; and Mellette, 0.11 inches; which ended with their driest April on record.

Madison, Roscoe, and Big Stone City recorded their second driest April on record, and another 11 weather stations recorded April 2015 among the top five driest on record.

“The dry situation has been a continuation of a weather pattern that set up in February, which resulted in longer term precipitation deficits,” Todey said.

Records for low precipitation are much more apparent looking back for the year-to-date, explained Laura Edwards, SDSU Extension Climate Field Specialist.

She went on to say that as of Jan. 1, 2015 several weather stations in the middle of the state documented January 2015 as the driest on record including: DeSmet, Forestburg, Murdo, Kennebec, Pierre, Wessington Springs, Madison and six others. “A few stations accumulated less than an inch of precipitation for the year so far,” Edwards said.

Another 33 stations ranked January through April 2015 as one of the five driest on record. “Across a large part of the state, these totals are less than half their average precipitation to this point in the year,” Edwards said.

In addition to lack of moisture, Todey added that nearly all of the state recorded above average temperatures for April. “Eastern parts of the state were warmest overall, with several places 4 to 5 degrees Fahrenheit above average for April,” he said. “Although, a few daily high and low temperature records were set in April, the widely varying temperatures for the year have left temperatures close to average so far.”

The dryness early in the spring was not a serious issue, and was actually beneficial for early agricultural work and livestock producers, explained Edwards. “However, now the precipitation deficits are having a negative impact on agriculture due to limited soil moisture, rangeland and forage concerns as well as some problems with seed emergence,” she said.

Along with the dry spring conditions, much of the state’s winter wheat crop experienced multiple challenges resulting from the dry fall conditions and low snow cover which resulted in winter kill.

The dryness has also obviously contributed to the large number of spring wildland and grass fires.

What current Climate and Drought Outlook have to say

The National Oceanic Atmospheric Association (NOAA) Climate and Drought Outlook for May 2015 tells us a little about where we might be headed, explained Todey. “Basically, the drought conditions are unlikely to make major shifts in the next month,” he said.

The NOAA U.S. Monthly Drought Outlook Map indicates drought conditions are likely to persist across the state and region, because precipitation totals are not expected to be sufficient to make large drought improvements.

“Precipitation deficits across most of the state are severe enough, that even with decent precipitation amounts, improvements will be difficult to see,” Todey said.

On average, in most areas of South Dakota, the month of May is the wettest month of the year. Moisture averages often total between 3 and 4 inches of precipitation. “Thus, larger precipitation totals will be needed not to lose more ground,” Todey said.

The NOAA Climate Prediction Center Precipitation Outlook for the next 30 days is not pessimistic, but Todey said it also not as optimistic as it is in some states to the south of South Dakota.

“The precipitation outlook indicates increased chances of precipitation along the southern edge of South Dakota and further south into the Central Plains,” he said. “Thus, areas to the south have better chances for drought improvement into May.”

Bottom line, Todey explained that the precipitation chances are equally as likely to fall below average as they are to fall above average. “In most years that would not be a major issue. This year, above average precipitation is needed to help overcome the deficits accumulated since last fall,” he said.

Crop losses are not guaranteed

This situation does not yet mean crop losses are guaranteed in all fields across the state, explained Edwards. “Winter wheat yields have been negatively impacted and rangeland will need precipitation very soon to limit losses, however due to the fact that April and May are critical months for summer forage production, and given the fact that corn and soybeans are just being planted this week, there is still time to limit damage to other crops across the state,” she said.

However, Edwards said regular, heavier precipitation amounts are needed to limit the problems for the remainder of the growing season.

“In general, summertime precipitation tends to be localized in thunderstorms, and not widespread events like we typically see in the winter season,” she said.

Throughout the growing season, SDSU Extension will publish frequent climate updates. To learn more, visit iGrow.org.