Abstract: A geostrophic wind forecasting method determines an atmospheric density (D) and a Coriolis parameter (F) at a given location. The atmospheric pressure is detected at the location over a predetermined period of time (t). The period of time (t), e.g., two hours, corresponds to the time required for a pressure surface to travel a distance (X) at an empirically determined velocity, e.g., 35 knots. The change in pressure (.DELTA.P) is detected over the period of time (t). The geostrophic wind velocity (VG) is then determined, according to the invention, based on the following relationship: VG=[1/(D.times.F)].times.[.DELTA.P/X]. The resulting geostrophic wind velocity (VG) is then displayed. At 35 knots, over a given two hour period, the distance X traveled by the pressure surface is approximately equal to 129,640 meters. The method is embodied in an apparatus that can be associated with a conventional barometer to produce a weather forecasting station.