The following is an email message sent to everyone in the Department on Monday, February 23 by Dr. Leila M. Vespoli de Carvalho, a UCSB Associate Professor of Geography who specializes in Meteorology and Climate Sciences:
If you were on campus around noon, trying to move from class to class or get lunch outside, you were probably surprised not only by the moderate rain but also by hail! It was quite exciting to see all this action during such a short period of time. It was not only your impression, but the storm was really short and small in size, only visible with high resolution 1km visible images.
You can blame the storm on a pool of relatively cold air in upper levels of the atmosphere (which makes it very unstable) and on the winds that forced moist air against the mountains. This is a good recipe for forming storms and the reason for the powerful cloud ‘cell’ that you can see in the VIS image attached in this message.
According to our local station on the top of Ellison Hall, we got about 0.17 inches of rain in 15 minutes! The drop in temperature during the storm was even more impressive: from 61.3F before the storm to 54.3 after the storm. Hail was big enough to be observed at ground level. Cold temperatures during the storm can be explained by evaporation of the water. Unfortunately, the machine that we use to run our mesoscale model is down, so we don’t know how well our model would perform in simulating this small but powerful system. Next time, maybe…
Editor’s note: The last notable hail in the Santa Barbara area occurred in 2001 when a freak hailstorm left an inch of hail on a quarter mile patch of the 101 freeway close to the county line near Ventura and caused several car accidents (source: LA Times, April 6, 2001, California Local News).
