August 3, 2018
By Doyle Rice
The devastating fire tornado (click here) that spun up during the Carr Fire last week had 143 mph winds, according to a preliminary report from the National Weather Service Thursday. This is equal to an EF-3 tornado on the five-level Enhanced Fujita Scale.
Dan Keeton, the meteorologist-in-charge at the National Weather Service in Sacramento, said the fact that the weather service was able to see the rotation of the 35,000-foot-tall plume on its radar — well over 100 miles south of Redding — was significant....
Urban Heat Islands
Heat islands (click here) form as vegetation is replaced by asphalt and concrete for roads, buildings, and other structures necessary to accommodate growing populations. These surfaces absorb—rather than reflect—the sun's heat, causing surface temperatures and overall ambient temperatures to rise. Displacing trees and vegetation minimizes the natural cooling effects of shading and evaporation of water from soil and leaves (evapotranspiration). Tall buildings and narrow streets can heat air trapped between them and reduce air flow. Waste heat from vehicles, factories, and air conditioners may add warmth to their surroundings, further exacerbating the heat island effect. Heat islands can occur year-round during the day or night. Urban-rural temperature differences are often largest during calm, clear evenings. This is because rural areas cool off faster at night than cities, which retain much of the heat stored in roads, buildings, and other structures. As a result, the largest urban-rural temperature difference, or maximum heat island effect, is often three to five hours after sunset. Other contributing factors to the heat island effect include:...
