Goryachev, Anatoli (Central Asian Research Hydrometeorological Institute)
Lyapina, Bella (same affiliation)
New forecast methods for the territory of the Central Asia are for the first time summerized and de- veloped on the basis of discriminant analysis for forecasting the processes of formation, evolution and dis- sipation of upper level depressions (cyclones having one or more closed isobars) and also related to them precipitation of different rates.
Statistical forecast technique of the following phases of upper level depressions development for the next day has been elaborated.
1. A cyclone initialization. The method is based on the great probability of cyclone formation in cold dep- ressions. P^=70-80%. 2. A cyclone allocation. The essence of this method lies in determing the centre of cyclone formation ac- cording to the position of the low temperature centre for the previons day. P=80%. 3. A cyclone stability (tt). The idea of this method is that stationary cyclones of the Central Asia are related to the existence of the Atlantic and Eurasian blocking systems. P=84% for tt more or equal 8 days, P=81% for tt equal to 1-2 or 3-7 days. 4. A cyclone movement (tracking). The method is based on the availability of surrounding cyclone thermobaric fields discrepancies. P^^=83% for direction and P^^=70% for velocity and direction of cyclone tracking; P^^^=80% for direction and P^^^=73% for velocity and direction of cyclone tracking. 5. A cyclone dissipation. On the basis of this method lies the known fact of cyclone dissipation under the influence of temperature increase in its low centre due to the transformational changes of the air masses.
P=80%. 6. Precipitation of different rates.
This method of forecasting is based on the revealed relations between precipitation amount for 12 hours and thermohydrodynamic characteristics calculated on the corresponding part of air particle trajectory.
P=65-85% (varying from the site of the region of precipitation forecasting).
The obtained results are published in monograph written by the authors in Russian (abstract is in English) under the title "Upper level depressions over the Central Asia", Tashkent, 1996.
^) P - total reliability of the forecast. ^^) P for the meridional tracking. ^^^) P for the latitudinal tracking.