Stormy Morning North-Central Plains

The 1145 UTC IR image (top) captures a large, classic from the satellite perspective, MCC over the north-central Plains. The composite radar image at 1215 UTC (bottom) shows a small, leading line of intense echo and a much larger line of thunderstorms to the west. At the time of these images, the bulk of the very large area of "stratiform" rainfall lies to the north (or left side) of the intense convective components (giving the system a complicated structure). This convective system had been moving eastward during the early morning hours, through a region of strong, warm advection associated with the nocturnal, low-level jet. It was not forecast well by the NAM in its 0000 UTC run (I'll show this in a later post).

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Back in the late 1960s and early 1970s, when I was a forecaster at Offutt AFB, south of Omaha, these early morning, summer convective events were somewhat of a mystery, and not forecasted well typically. The first such system I ever personally experienced was on a Saturday morning at sunrise, when I was driving to my then assigned duty location - the Air Defense Command blockhouse in Sioux City, Iowa. This was in June 1968, and the Weather Bureau forecast for the day came over the radio while I was heading south in a chilly, steady moderate rain - "sunny and hot today," read by the announcer with a snide chuckle. During the next few years, south a bit at Omaha, I would experience many more such systems. Part of the forecasting diffciulties related to the fact that there were no WSR-57 radars west of Grand Island, Nebraska, and most surface observing stations out across the western Plains shutdown at night. Meteorological satellites and numerical forecast models were in early development stages, thus the great forecasting challenges. The importance of accurate forecasts at Omaha was greatly amplified on the weekends. This was the height of the Vietnam War era, and there were more than a dozen Generals stationed at Offutt. In spite of the war situation, most of the Generals (Colonels too) would have tee-times on Saturday and Sunday mornings. A busted forecast for the morning rounds of golf would cause a great, local storm of disgust to fall on the weather guys from those above us. Motivation to learn more about these events was thus very great.