By R. Humphrey

Introducing "UFOs"; The truth is out there...

Coordinated by Tammy Weckwerth (a PECAN PI from NCAR) during non-IOP nights, PECAN participants will occasionally be conducting nocturnal Unofficial Field Operations (UFOs) in an attempt to capture unexpected, "surprise" meteorological phenomena which may not ordinarily be captured by instrumentation and which are difficult to forecast due to a lack of large-scale forcing.

Examples of UFO missions include: 1) deployments when PIs see a gust front, bore or MCS approaching Hays, 2) potential CI missions when there is a *possibility* of CI, but not a great enough chance to organize an official CI IOP and 3) monitoring deployments for afternoon to evening transition (AET) scenarios for boundary evolutions.

Above, DOW7 sets up outside the town of Galatia, KS as it participates in its first UFO mission on 18 June.


The motivation for conducting these flexible, short-term field operations is to take observations using the mobile instrument platforms more frequently than during official IOPs, at very short notice. The hope is to spread out the instrumentation assets during the off-peak, unofficial IOP times while collecting even more scientifically useful data.

A UFO may be called on "down" nights when an official IOP is not scheduled. Participation in any UFO is completely voluntary, and all instrument platforms are encouraged to attend/participate. The participating platforms would likely include mobile PISA members CLAMPS (MP1), MIPS (MP2) and SPARC (MP3), FP3 (Ellis) flying the Millersville tethersonde, FP2 (Greensburg) with ALVICE and GLOW. Limited radiosonde launches are possible via different groups. Mobile radars may include MAX, Rax-Pol and 1-3 DOWs. Mobile lidar T-WOLF will participate.

These missions are slated to be conducted close to the Hays, KS base, usually within 30 minutes of the FHSU campus, and are expected to last anywhere from 2-5 hours depending on the weather phenomenon to be observed.

The most recent UFO mission was conducted on 18 June, and involved CLAMPS, MIPS, T-WOLF, S-Pol, three DOWs, and a mobile mesonet vehicle which conducted transects and launched a radiosonde. As a result, the groups captured the evolution and propagation of a boundary that moved from the NE to the SW around midnight UTC (7pm local time.) Several additional wave-like patterns in the scattered high-altitude clouds were captured by the remotely-sensing instruments.

Today's contributing author is Rachel Humphrey, support scientist at CSWR. You can follow her on Twitter at @GoAskAScientist.