Rules of Thumb for Weather Forecasting. AOS 452. 11 October 2005. There's a 50% chance of (insert weather condition here) Bad GEMPAK analysis.
Forecasting 'rules of thumb'. Some techniques, largely empirical, for use by ' single observer forecasters'. Often rough & ready, but over time have been proven to.
On the 700 mb forecast chart, the 90% relative humidity line often encloses areas where precipitation is likely. If upward velocities are present, the chance of.