What significant event occurred at Wichita Falls based on the METAR report?

The correct choice indicates that a funnel cloud was observed, which is a significant event in meteorology as it can lead to severe weather phenomena, including tornadoes. A funnel cloud is a rotating, condensation cloud that extends from a thunderstorm and is typically associated with severe thunderstorms. The observation of a funnel cloud provides critical information about the local atmospheric conditions and potential for severe weather, alerting meteorological and emergency services to take necessary precautions.

The other options, while they may reflect changes in weather conditions, do not carry the same level of severity or immediate impact as the presence of a funnel cloud. For instance, variability in atmospheric pressure might suggest changing weather patterns, but without the indication of severe weather, it is less alarming. Similarly, if rain becomes lighter, it indicates a shift in precipitation intensity but does not imply any urgent weather threats. A sharp increase in temperature can indicate various phenomena but is less directly related to severe weather events compared to the presence of a funnel cloud.