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Base reflectivity data is one of the basic products
available on the WSR-88D. Reflectivity shows where and how hard
it is raining or snowing, as well as precipitation intensity
trends and movement. Blue and green colors represent light-to-moderate
rainfall. Yellow and orange colors show moderate-to-heavy precipitation,
while red is very heavy rainfall and possibly hail. At left is a close-in
view of a portion of a squall line over parts of south-central Indiana and
northwest Kentucky. Forecasters identify reflectivity signatures to determine potential storm
severity. In this case, a bow
echo within the line was located across Daviess County, which was
producing a damaging tornado at this time in Owensboro on January 3,
2000. A weak echo channel (axis of lower reflectivity values) was
located across southwestern Daviess County just behind the bow apex,
indicative of strong straight-line winds as well. Also note the tight
reflectivity gradient on the leading edge of the line, a signature typically
associated with severe storms. Other strong storms were located
farther north and south along the line. |
