THE FORECAST PROBLEM 
By H. C. WILLETT 
Massachusetts Institute of Technology 
INTRODUCTORY REMARKS 
The Unsatisfactory Progress of Weather Forecasting 
as a Science. Probably there is no other field of applied 
science in which so much money has been spent to 
effect so little real progress as in weather forecasting. 
Today the nations of the world spend many times what 
they did forty years ago to obtain the necessary observa- 
tional data and to prepare weather forecasts. But the 
advance in weather-forecasting skill has not kept pace 
with the increased effort and attention devoted to 
forecasting. The variety of weather forecasts, as to 
time range and detail, as to the elements forecast, and 
as to the elevations and geographical areas for which 
forecasts are prepared, has been greatly imcreased in 
proportion to the increase in the observational synoptic 
data, to meet more exacting demands. Much has been 
done to meet these demands by the development of 
special types of forecasts, frequently forecasts of ele- 
ments which were not even observed forty years ago. 
But in spite of all this great expansion of forecasting 
activity, there has been little or no real progress made 
during the past forty years in the verification skill of 
the original basic type of regional forecast, of rain or 
shine and of warmer or colder on the morrow, the kind 
of forecasting which first received attention. 
The question naturally arises, Why has this great 
expansion of forecasting activity contributed so little 
to the basic advance of the science? There are a number 
of factors to which this lack of progress may be at- 
tributed. These factors vary somewhat in relative im- 
portance from country to country, but probably 
conditions in the United States (which has experienced 
perhaps the greatest multiplication of forecasting tools 
and techniques) may be taken as essentially typical of 
the entire field. On this assumption the principal reasons 
for the failure of forecast skill to keep pace with forecast 
practice are: 
1. The expanding demand for trained forecasters. 
Since World War I, but increasingly during the thirties 
and with the outbreak of World War II, there has been 
a vast expansion in the number, the variety of service, 
and the trained-personnel requirements of weather- 
forecast centers. This greatly increased demand for 
forecasters has come from government weather bureaus, 
from commercial aviation, and from the military. Since 
the vastly increased demand for trained forecasters was 
not anticipated, the proper training of large numbers 
of forecasters was not provided for. Neither has suffi- 
cient salary incentive been provided (in proportion to 
the exacting nature of the work) to attract into this 
field, or to hold, the best-qualified men. As a result, 
thousands of meteorologists have been pressed into 
forecasting service, many of them after only one or two 
731 
years of training, and many of them unqualified by 
interest or temperament for this work. One further 
circumstance which has been most unfavorable to the 
improvement of forecasting is that by and large there 
has been in operation no objective verification pro- 
cedure by which the forecasting ability of these many 
inexperienced forecasters could be compared one with 
another or against any standard, as a basis for the elim- 
ination of the less competent forecaster. 
As recently as twenty years ago in the United States 
the few official government forecasters were assigned to 
this duty only after many years of practice forecasting 
in objectively verified competition with the official and 
other practice forecasters. After assignment to forecast 
duty their records as official forecasters were continu- 
ously checked in the same manner. It is a sad com- 
mentary on the scientific status of weather forecasting 
that even today the methods remain so empirical and 
so dependent upon experience and subjective interpreta- 
tion that the development of the best forecasters still 
requires years of experience and the right temperament 
and interest. The primary problem of weather forecast- 
ing remains that of removing the science from this sub- 
jectively empirical category and of making it scien- 
tifically objective. 
2. Multiplicity of forecasting tools and techniques. 
The availability of rapidly increasing amounts of ob- 
servational synoptic data, particularly of aerological 
data, has led to a great amount of experimentation with 
the use of various charts and coordinate systems for 
the synoptic presentation and analysis of the new 
observational material as an aid to the forecaster. 
Unfortunately this has led to the introduction into 
forecasting practice of a multiplicity of charts and dia- 
grams which are largely redundant in that they present 
the same basic information in a variety of forms, the 
relative merits of which remain completely untested, 
and the variety of which leads only to a confusion of 
forecasting techniques and principles that interferes 
with the clear-cut formulation of any simple set of prog- 
nostic rules or criteria, such as is gained from long 
familiarity and practice with one minimum standard 
set of synoptic charts. At the present time routine fore- 
cast practice can undoubtedly be greatly benefited by 
the universal acceptance of a minimum standard set of 
simple synoptic charts, even though the selection of the 
standard aerological charts might not be the most 
effective that could be made. This selection of standard 
charts should be based on some real attempt at objective 
verification of their relative prognostic merits, a pro- 
cedure which is equally necessary for forecasting tech- 
niques and for forecasters. 
3. Failure to assess the essential forecast problem 
correctly. Probably the primary reason that more prog- 
