Ag Weather Forum

Perspective On Summer

Bryce Anderson
By  Bryce Anderson , Ag Meteorologist Emeritus
Connect with Bryce:

After this late spring round of heavy rain, severe weather and numerous planting delays, there are reasons for a very cautious tone when it comes to thinking about the summer forecast. I emphasized that idea in a recent article for The Progressive Farmer magazine. Here are the lines from that article relating to the summer 2013 forecast:

For the heart of the growing season, during summer 2013, two recent large-scale features will wrestle for atmospheric supremacy--the tendency for high-latitude blocking high pressure to form and maintain its presence for a period of months, and the pervasive drought pattern in the southwestern Plains through the southwestern U.S. These features have shown their potential for weather dominance recently. The northern-latitude blocking high pressure feature was prominent in 2008 and 2009, when consistently cool temperatures all season long helped crops to go through their filling stages with very little stress. Those two years brought some large yields. In contrast, the influence of the drought pattern over the southwestern Plains and southwestern U.S., in our view, was a definite contributor to the late-summer dryness in 2011, and reinforced the drought of 2012.

We also are mindful of some longer-term tendencies that have been a part of the weather scene during the past several decades. The first overall, longer-term trend is for generally warmer temperatures, especially in the central part of the country, and more specifically during the overnight hours. This pattern was very prominent in the past three years--and in those three years, corn yields were below trendline for the first three-year consecutive period since the early 1950s, when hybrid seed was widely adopted by growers. A second longer-term feature is the tendency of rainfall to be less spread out during the year; precipitation has shown the trend of heavier individual events, and occurring during spring, then tailing off notably during the summer. So, while annual precipitation has increased in some areas, the timing has been skewed away from offering those midseason doses of moisture that crops need and producers love to see. So, these two features get involved in the outlook as well. Taken together, they create a widely varied mosaic for this season.

Looking ahead to the summer, here is a regional rundown:

P[L1] D[0x0] M[300x250] OOP[F] ADUNIT[] T[]

MIDWEST: We look for temperatures to be above normal, even in the northern sector of Minnesota and Wisconsin, where conditions were mild and the most favorable during 2012. A solid above-normal tendency is in effect over the vast majority of the region. Precipitation--near normal. But, with the outlook for heat to be a notable feature, and even though conditions do not look as hot and dry as they were in 2012, irrigation systems that have sprung up all over the region will likely get called on again.

PLAINS: Temperatures will be above normal in all areas. There is also a hot area from central Wyoming south to the western Texas Panhandle and including almost all of Colorado and New Mexico. Dryness again shows up in some sectors, including the northwestern portion in Montana and the far southwestern portion of the region. Meanwhile, the southeastern portion of the region could show a heavier precipitation trend. So, the line between "have" and "have not" on rainfall could be a very sharp divide. And, in some southwest areas, and as difficult as it sounds, drought may enter its fourth straight year in some areas of the region.

DELTA: Temperatures are on track to be above normal, with precipitation near normal. It does not appear that the Delta faces a potential midsummer drought playing havoc with yields.

SOUTHEAST: After generally recovering from drought, the Southeast has a warm temperature pattern and near-normal precipitation in store during the summer season. The best chances for moisture show up in the Atlantic coast portions of the region.

FAR WEST: Temperatures and precipitation exhibit near-normal trends for both these features. However, this region could still be short on available crop moisture; after all, the region is coming out of a spring period which featured severe drought in many areas.

NORTHWEST: Temperatures show a trend of near to above normal, so some warm conditions are indicated for the summer time frame. The biggest issue is that of precipitation. Moderate drought began creeping into Oregon and northern California last spring. Now, that feature looks ready to expand into the rest of Oregon and Washington during summertime.

As with any weather scenario during this very-active stage of the crop cycle, the timing of precipitation will be as key--or close to it--as the amount of moisture that falls. We even saw that last year--when some areas got a very timely rain from deteriorating Hurricane Isaac during the Labor Day weekend. The summer weather story again presents itself as one which will command lots of attention throughout its evolution.

Bryce

Twitter @BAndersonDTN

(AG)

P[] D[728x170] M[320x75] OOP[F] ADUNIT[] T[]
P[L2] D[728x90] M[320x50] OOP[F] ADUNIT[] T[]

Comments

To comment, please Log In or Join our Community .