TOP SECRET Conclusion. 6. Snow is likely in Yugoslavia within the next few days and will be deep enough to affect operations within a month. This together with the inactivity of Soviet troops makes it unlikely that an attack is contemplated in the immediate future. The recent restrictions in flying over Hungary might however indicate the initiation of measures to cover preparations for an invasion next spring. (Signed) W.G. HAYTER E.W.L. LONGLEY-COOK V. BOUCHER (Acting D.M.I.) L.F. PENDRED. Ministry of Defence, S.W.1.