Field campaign folklore tells us that if the climatology for a region suggests you expect a certain weather regime and you venture into the field looking for those conditions you are bound to get something else. The history of atmospheric science field campaigns is littered with those looking for one thing and finding another.

MC3E got off to a great start at the end of April with a few great precipitating convective cases coming right over the site and being sampled by two NASA aircraft, MC3E radars, and all of the other ground instrumentation. Since that time, we have been dealing with a blight of clear sunny days (only a meteorologist leading a precipitation field campaign would refer to a bunch of sunny days as a “blight”). These days offer a great opportunity to make any instrument repairs, get documentation and initial data analysis done, take care of other work duties and also mundane tasks of our normal lives like laundry and haircuts. But for those of us with visions of historical field campaign data sets, conference presentations, and journal articles dancing in our heads, the sunny clear days cannot end soon enough.

So, with our fingers crossed and our hopes high, we came to the morning weather briefing on Wednesday, May 11, hoping to hear some good news. The anticipation of good weather conditions in north-central Oklahoma was somewhat dampened by complicating factors such as indecisive model forecasts, a possible upslope precipitation event in Colorado (a fall-back option for operations) and the chance of severe weather at Offutt Air Force base (where the ER-2 is stationed) that would prevent the ER-2 from landing after it completed a mission. A tough decision for Walt Petersen and Larry Carey, the mission scientists for the day, but they decided to pursue some morning convection that had already formed over the Texas panhandle and was expected to propagate over the ARM Central Facility by the late morning, early afternoon. There was the chance this convection would fizzle out and the Colorado precipitation would grow or there was the chance the ER-2 would be called back to Offutt before it could sample anything near the site, but this seemed like the best of the options. As the convection moved towards the site, the ER-2 was able to fly over some of the convective cores, and then perform a couple stacked legs in the stratiform rain with the UND Citation. This should be an excellent data set even if it was not directly over our surface instrumentation.

At about the time the ER-2 was called back to Offutt before the weather there would make it impossible to land, the eastern edge of the rainfall began reaching the ARM Central Facility. The green flag outside the main operation building, which indicates clear weather and no safety hazards, was soon switched to red with the accompanying announcement of a weather alert, lightning in the area and the ceasing of all outdoor activities. The lightning, precipitation, storms and clouds is exactly what MC3E is here for… Finally!

The Citation did some additional sampling in the stratiform rain over the site, but soon encountered some bumpy, embedded convection and was directed to head to home. Air traffic control and the developing intense convective cells had different ideas though. As the strongest convection developed over the Ponca City airport, Kansas City ATC diverted the Citation from a quick run around the northern extent of the storms while alternative landing options were considered. The Citation wound up diverting to Tulsa for a few hours, waiting out the storm, and returning to Ponca City later in the evening.

In the meantime, those of us on the ground watched as the ground radar systems sampled the storms in the domain with all the different frequencies and scanning modes. In the end, this should be a great data set to investigate many different aspects of convective storms. Lots of difficult decisions today, but a great job by all—particularly our forecasters, mission scientists, Citation crew, and ER-2 crew.

Editor’s Note: Mike Jensen is the principal investigator for the MC3E field campaign.