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of January 3-5, 2005 Answer to Question 8 |
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8. Still 5:00 pm Tuesday. Examine the 5 cm soil temperatures, under native sod (blue) and under bare soil (red). The Mesonet air temperature freezing line is still in pink. Some recent Local Storm Reports (LSRs) from Norman are given below.
- Based on the soil temperatures, do you think much ice is sticking to the ground in northwestern Oklahoma?
- Focus on the temperature, wind and rainfall panels of the Buffalo and Alva meteograms. What clues do they give you about whether ice is accumulating on the ground? On elevated structures?
Answer.
- Five-centimeter (two-inch) deep soil temps are in the mid-30s to low-40s throughout northwestern Oklahoma. 5cm soil temps will tend to lag behind (cool more slowly) the surface conditions, but temperatures near 40 are usually sufficient indicators that the surface hasn't yet cooled to 32F.
- The Alva and Buffalo meteograms show evidence of icing on elevated structures (such as tree limbs and power lines). They also show evidence that the ground-level is not yet seeing accumulations of ice.
- Both sites show temperatures that have been below freezing for several hours.
- Wind speeds diminished to near zero during the morning, and the wind direction stuck in a constant direction. These indicate the freezing up of the 10-meter-high Mesonet wind monitor.
- On the other hand, each meteogram shows rainfall accumulations continuing into the afternoon. This is an indication that surface-based objects (like the Mesonet rain gauges, which are not heated) are not yet freezing up.
The Bottom Line:
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Meteograms can give you a number of clues regarding just about any critical weather situation. Winter weather is no different.
OK-FIRST Project, Oklahoma Climatological Survey, 100 East Boyd, Suite 1210, Norman, OK 73019
Copyright © 1996-2005 Oklahoma Climatological Survey. All Rights Reserved.
Send comments or questions concerning OK-FIRST to okfirst@mesonet.org.