Crack – Crash – Shatter
Another limb just broke and fell to the ground with ice shattering like glass from the impact. As I’m trying to find ways to monitor whether the ice is getting worse or melting, I remembered that the Oklahoma Mesonet has air temperature sensors at two heights. The Inversion Map shows both air temperatures.
The most reported air temperature is the one from the 1.5 meter (5 feet) Mesonet sensor.
The Mesonet also has a air temperature sensors at 9 meters (29.5 feet).
In an ice storm, the 1.5-meter air temperature near the ground gives us a clue as to what is going to freeze to shrubs, fences, walkways, and low bridges. For the tops of trees, power lines, and taller bridges, the 9-meter air temperature can let us know what is going on.
For an ice storm, tenths of a degree matter. So while the statewide maps are handy, to see tenths of a degree one can turn to the Mesonet Meteograms for a single Mesonet site. Here is a chart for Chickasha. It shows a slow warming trend for both 1.5 and 9 meter air temperatures. At 12:40 PM on November 28th, both temperatures have crept above freezing. Additional rain is not adding to the ice load, ice has started to melt, and some ice is slipping off trees and shrubs.
Twenty miles to the north at Minco, air temperatures are stubbornly remaining below freezing. Additional freezing rain will just add to the risk of more trees branches breaking and power lines coming down.
Now, we just need the wind speed to stay low until melting can occur.
