Forecasting Notes and Information
Loaded Gun Storm Chasing
website of storm chaser Mikey Gribble
Bulk Richardson Number - Multicell Storms = R > 30 Supercells = 10 < R <40
(Doswell)
According to Weisman and Klemp storms are likely to be multicell whenever BRN > 45, and may be supercell
when BRN < 45. When BRN is < 10 with undirectional shear, storms may be supressed by the excessive
shear, although with curved hodographs this suppression is less noticeable. (McCaul Jr., Steve Lazarus, and
Fred Carr)
Cloud Cover - Any areas where the isotherms cross the height contours often idicate potential areas of cloud
and precipitation development. Dewpoint depressions of 5 degrees C or less outline areas of possible clouds.
(Tim Vasquez)
On the 700mb chart, the 70% relative humidity line usually encloses areas that are likely to have cloud cover.
90% relative humidity on the 700mb chart usually means rain.
Short Waves (Doswell)
Short waves tend to move at a speed proportional to the average wind speed near the 700mb level.
- when a short wave moves into a trough the trough (long wave) tends to deepen
- short waves tend to deepen when they approach a trough and weaken when they approach a ridge