I would expect the volume of harvests to stay about the same, the number of fishermen to stay about the same and the number of flights to stay about the same.
There would likely be more lost crops and more accidents though (just not a huge percentage of lost crops or enough accidents to dissuade people).
> the value of weather and climate information itself has been shown to be relatively small as a percentage of the economy.[33] However, when dealing with weather and climate where each year billions of dollars of property is damaged and many lives are lost as a result of severe weather events, even a small improvement in predictive capability can add up to major savings.[34]
Where [33] is "A good review of some of the economic issues in measuring the value of weather information can be found in Molly K. Macauley, “Some dimensions of the Value of Weather information: general principles and a taxonomy of empirical approaches,” http://sciencepolicy.Colorado.edu/socasp/weather1/macauley.h...
That affirms 'Most estimates of the value of [weather prediction] information suggest that it is not large as a percentage of final output.'
There would likely be more lost crops and more accidents though (just not a huge percentage of lost crops or enough accidents to dissuade people).