Fijgrtoft, baroclinic wave studies by, 
459 
Flame collector, 148 
Floceuli, 379 
Flood routing, 1051 
storage routing, 1051 
Flood water run-off, applied climatology 
and, 987 
Flow, steady-state, under inversion, 
equations for, 430 
time-dependent, as forecast tool, 430 
under an inversion, 424 
two-dimensional steady, 431 
under an inversion, 424 
effect of Coriolis force on, 432 
Flow patterns, midtroposphere, progno- 
sis, 810 
Fluid currents, incompressible, pertur- 
bations in, 412 
Fluid motion, baroclinic instability in, 
468 
centrifugal instability in, 467 
generalized vertical-overturning in- 
stability, 468 
gravitational-centrifugal 
in, 467 
gravitational instability, 467 
Helmholtz instability and, 468 
instability, general theory of, 466 
Foehn, 667 
clouds associated with, 667 
desirable studies, 671 
development, 668 
free, 668 
high, 668 
islands, 668 
north, 668 
nose, 667 
pauses, 669 
south, 667 
thermodynamic explanation, 667 
Fog, 1179 
advection-radiation, 1184 
forecasting, 1186 
advective marine, drop size, 170 
air-mass, 1183 
artificial dissipation, 178 
classification, 1183 
clearing, forecasting, 1187 
cold front, 1184 
definition, 1179 
Eisripacion, artificial, economics of, 
1 
instability 
effect of atmospheric pollution on, 1148 
forecasting methods, 1185 
formation, 1179 
drop-size distribution, 1180 
liquid-water content, 1180 
over snow cover, 1181 
physical processes, 1181 
research needed, 1182 
role of condensation nuclei, 1179 
frontal, 1183 
land- and sea-breeze, 1183 
liquid-water content, relation between 
visibility and, 1180 
mixing-radiation, forecasting, 1187 
postfrontal, 1184 
pre-warmfrontal, forecasting, 1187 
restricted heating, 1185 
radiation, 1184 
drop size, 170 
forecasting, 1185 
graph, 1185 
sea, pioud drop-size-distribution in, 
forecasting, 1185 
smog, 1179 
smoke, 1179 
steam, 1183 
synoptic aspects, 1183 
upslope, 1183 
Fogbow, 70 
Forecast districts, 768 
INDEX 
Forecast problem, 731 
essential nature, 732 
failure to assess, 731 
scope, 732 
Forecast terminology, 842 
Forecast verification, 841 
adjustment for difficulty, 846 
contingency-table summaries, 843 
control forecasts, 846 
correlations, 845 
forecast-reversal test, 847 
methods, 843 
percentage correct, 844 
pitfalls, 847 
probability statements, 845 
problem of, 841 
purposes, 841 
administrative, 841 
economic, 841 
scientific, 842 
selection, 843 
research needed, 847 
root-mean-square-error, 844 
scores, arbitrary, for special purposes, 
846 
scoring, 843, 844 
Forecasters, demand for, 731 
selection, 743 
training, 743 
Forecasting see also Forecasts 
aids, 733 
air mass modifications, 779 
air current modifications, 779 
aircraft icing, 793 
conditions, 1201 
analogue, 738 
anticyclogenesis, 770 
anticyclones and, 626, 778 
approach, 744 
area forecast, 767 
by statistical methods, 849 
cold air-mass hydrometeors, 789 
continental factors, 739 
cyclones, 778 
eyclogenesis, 770, 1175 
diffusion conditions in atmospheric 
pollution, 1151 
dynamic, advective models and, 471 
by numerical process, 470 
computational stability, 477 
frictional effects, 482 
geostrophic approximation and, 470 
linearized barotropic model, 474 
nonadiabatic effects, 482 
nonlinear barotropic equation, in- 
tegration of, 478 
objective analysis, 479 
use of primitive equations, 480 
equatorial, 885 
extended-range, 802, 814 
by weather types, 834 
research needed, 840 
critique of methods of, 828 
definition, 802 
interaction on a hemispheric basis, 
838 
relationship between circulation and 
weather, 809 
research needed, 812 
scientific bases, 814 
techniques, common factors in, 834 
extrapolation, computational tech- 
niques, 738 
mathematical techniques, 738 
techniques, 734 
fog, 1185 
front modifications, 779 
frontal occlusion, 778 
frontal weather, 650 
frontogenesis, 770 
hydrometeors, general, 788 
warm air-mass, 789 
improvements needed, forecasting 
techniques standardization, 741 
1323 
Forecasting—continued 
improvements needed—continued 
recommendations for, 740 
technical, 740 
weather observations, 741 
linear extrapolation, 736 
long-range, 831 
extrapolation of periods, 831 
extrapolation techniques, 734 
multiple correlation tables, 831 
regression equations, 831 
symmetry points, 831 
synoptic extrapolation, 737 
synoptic-statistical techniques, 811 
mathematical, 470 
medium-range, cireulation, physical 
methods in, 806 
upper waves, 806 
French methods, 804 
mean-circulation methods, 829 
methods, 804 
method of singularities, 804 
methods, analogue, 806 
weather type, 806 
problems, 802 
sea-level pressure distribution, 828 
statistical methods, 804 
symmetry-point technique, 806 
midtroposphere flow patterns, 810 
movement of sea-level pressure sys- 
tems, 776 
objective, 796 
and applied climatology, 986 
combined deductive-empirical meth- 
ods, 799 
investigation goals, 796 
limitations, 797 
methods of deriving aids, 799 
numerical calculation, 798 
problems, 796 
research needed, 850 
statistical methods, 798 
testing procedures, 850 
types, 798 
ocean waves, 1082 
oceanographic factors, 740 
of various weather constituents, 787 
physical factors, 739 
physical techniques, 739 
practical, general principles, 766 
problems, 731 
projecting centers of action, 811 
regional vs. global approach, 744 
river see also River forecasting 
river, 1048 
Rossby’s vorticity technique, 739 
scientific, problem of, 744 
short-range, 747 
a procedure of, 766 
aids, objective, 762 
analogues, 737, 750 
basic surface chart, 749 
charts and graphs, 748 
cloudiness, 760 
clouds, 753 
constant-pressure charts, 749, 751 
cyclone movement, 752, 1171 
empirical forecast rules tests, 762 
fog, 761 
guides, climatological-statistical, 
762 
main centers of action, influence, 
759 
700-mb chart, preparation, 753 
700-mb prognosis, operations in 
making, 754 
observations, 748 
organization of, 762 
physical techniques, 739 
pilot-balloon charts, 748, 753 
precipitation, 760, 790, 1168 
preforecast study, 758 
present state, 747 
