| weather factors in the prediction of western equine encephalitis epidemics in manitoba. | cases of western equine encephalitis in horses in 1987 in western usa and manitoba, canada were examined by backward trajectory analysis of winds. culex tarsalis mosquitoes infected with western equine encephalitis virus could have been carried on southerly winds from texas and oklahoma to northern usa and from there to manitoba. the presence of the polar front over north dakota and minnesota at the end of july would have led to the landing of cx. tarsalis in montana and wisconsin and prevented ... | 1993 | 8405163 |