How to decide when the forecast is still uncertain

A forecast gives a 60% probability of rain. The person organising the work may feel obliged to suspend it, even though there is still a considerable chance that it will not rain. At 30%, they may decide to go ahead without further thought, although rain remains possible. In both cases, turning the percentage into a yes or no avoids an uncomfortable part of the decision: considering what to do if the less likely outcome occurs.

Uncertainty does not disappear when the day's work is organised. The company has to work with it by comparing the consequences of acting and waiting. Sometimes another update can be consulted before resources are committed. That possibility has value as long as there is still time to do something with the new information.

Today, there is still time to wait

Imagine a banana farm with a foliar application planned for Thursday. It is Tuesday morning. In this example, organising the equipment and staff takes one day, so the decision must be made by Wednesday morning. The schedule and timing are hypothetical.

The manager is concerned about rain during the period in which the product needs to remain on the plant. That period depends on the product and its conditions of use; the probability of rain over the entire day may be too general for this decision.

Tuesday's forecast leaves doubt about the work window. Applying means committing resources that could be lost if conditions prove unsuitable. Rescheduling also has consequences, which the agronomic manager must assess. Neither option is free.

Suppose that, for now, the information does not distinguish clearly enough between the options and that keeping the decision open until Wednesday would not mean losing the equipment or the work window. Under those conditions, waiting for another update may be reasonable.

For that wait to be useful, someone must take responsibility: check Wednesday's forecast at an agreed time and confirm or reschedule the work. The team must also define what change in the forecast would favour one decision over the other. Otherwise, it is easy to reach the next morning and repeat the same conversation.

Tomorrow may bring more information

On Wednesday, the new forecast might indicate conditions that are more favourable for the application. It might also raise the probability of rain and provide a reason to reschedule. If either change helps avoid an unsuitable commitment, waiting will have been useful.

An update does not guarantee that the doubts will be resolved. It may show possibilities that previously seemed unlikely, or leave the situation much the same. Being closer to the event often helps us anticipate it; that does not mean every new forecast is necessarily more accurate or presents a narrower range than the one before.

The decision to wait is therefore made before anyone knows how much the information will improve. What might be learned must be compared with what is lost through delay. If waiting makes hiring more expensive or no longer secures the equipment, that cost enters the comparison. If the action could no longer be changed, consulting another update adds no value to that particular decision.

At the banana farm in this example, there was time to wait on Tuesday. The farm could use that time without giving up the option of carrying out the work on Thursday. This is the condition that must be checked in each operation.

A decision must be made on Wednesday, even if doubts remain

The agreed time arrives and the forecast remains uncertain. The team must confirm or reschedule using the available information, considering both the risk of rain and the agronomic consequences of changing the date. Neither option may feel comfortable.

Waiting until Thursday morning would no longer preserve the same possibilities. Because preparing the application takes one day, by then the option of carrying it out as planned would have been lost. The delay would have had an operational consequence even if no one had communicated a decision.

That limit should be written down on Tuesday: who decides on Wednesday, at what time and with what information. If a later update still arrives in time to change part of the work, it can be used. The deadline depends on what can still be changed in practice.

What to review afterwards

If the application is rescheduled and it does not rain on Thursday, there will be a cost to review. The same is true if the schedule is kept and it rains. The outcome deserves attention, but the evaluation must include what was known while there was still room to choose.

Keeping the forecast that was used and the time of the decision makes it possible to check whether waiting added information, whether the team met the deadline and whether the assumed costs were reasonable. Once several decisions have been recorded, it will be easier to recognise when another update is worth waiting for and when the delay uses up time the operation needs.

For the next application, the manager will have more than the rain probability: they will know how long they can wait and what waiting entails.