Which forecast horizon does each decision need?

A flower farm preparing production for Valentine's Day makes decisions long before February begins. It must schedule the crop and, later, organise cutting and delivery. When only a few hours remain before a cold night, it may still be able to adjust how the greenhouses are managed. Each of these decisions needs different information.

Forecasts for the coming months, days or hours become meaningful when they are connected to this work. How much advance notice a farm needs depends on how long it takes to prepare an action and the latest time at which that action can still be changed. The next question is whether weather information useful enough for that time frame is available.

Months ahead: prepare production

Consider a farm in the Ecuadorian Andes with a committed delivery date. To schedule production, it draws on experience with the varieties it grows, its records and its management conditions. Temperature during development is one of the variables it considers. If the season differs from usual, the planned schedule may need to be adjusted.

A seasonal forecast may provide information about the probability of conditions being warmer or cooler than a climate reference. The reference period, location and months concerned must be clear if the information is to be interpreted correctly.

This information can help the farm compare production scenarios. For example, it can assess how much room it would have if development ran early and what alternatives would remain if it ran late. The forecast becomes one input to planning that already considers other sources of variation; on its own, it does not determine the cutting date for a variety.

Its limits also need to be understood. A product that extends several months ahead is not necessarily useful for temperature at that farm at that time of year. Its performance must be evaluated for the question being asked. When the signal is weak, planning will need to preserve a larger margin.

A phone app may show the weather for the next few days in considerable detail. That detail does not extend to the months needed by the person planning the season.

Days ahead: organise the work

Once production is further along, the farm can observe the state of the plants. It now needs to allocate staff, order the work blocks and coordinate use of the cold room. Fewer options remain than at the start of the season, although some decisions can still be moved from one day to another.

The weather forecast for the next few days can help compare those windows. The question becomes specific: what conditions are expected during the planned work, and with what uncertainty? The information must correspond to the place and period of interest and arrive far enough in advance to organise the people involved.

A forecast of a warm season does not answer these questions. A warm season may still contain cold days. By the same token, one cold day is not enough to assess whether the seasonal forecast was accurate; that requires reviewing the period and the variable the forecast concerned.

At this stage, the observed state of the crop is combined with the forecast for the next few days. A decision made months earlier may be revised within whatever margin remains, but some commitments will already have been made. The farm must distinguish which ones can still be changed and what changing them would cost.

Hours ahead: adjust a prepared action

During a cold night, a greenhouse manager may need to decide when to apply a protection measure that has already been planned. Local conditions, their recent evolution and the information available for the next few hours all matter.

Nowcasting addresses this very short time frame and uses recent observations to track and anticipate how the weather will evolve. Its usefulness depends on the phenomenon, the available data and the location. The term does not imply exact knowledge of what will happen over every greenhouse throughout the night.

Some preparation will have had to take place earlier. If a measure requires staff who take several hours to arrive, waiting until the last moment to call them may put the measure out of reach. An update close to the event is more useful when the team already knows what it can do with that information.

Write down the timing of your own operation

The exercise can begin with a single decision. Write down how much time passes between authorising the action and having it ready. Include the usual delays, such as staff availability, confirmation of a service or reorganisation of other work. Then set the latest time at which an update could still change something.

If organising a crew takes one day, the information used to call it in must allow at least that much time. If scheduling production takes months, the company will need to work with seasonal information and scenarios. When the available forecast does not provide enough advance notice or detail, that limit should be made clear when the decision is designed.

The result will be a calendar of decisions with different information needs. Some will be reviewed as the date approaches; others will be fixed much earlier. Writing it down makes it clear which update to wait for, who should read it and what work can still change in response.