Every hurricane season, the same pattern plays out in Grenadian WhatsApp groups. A tropical wave leaves Africa, someone shares a long-range model run showing a hurricane over the island in ten days, a voice note follows warning of a monster storm, and by evening half the village is in the supermarket. Most of these systems fade or pass far to the north. Then, occasionally, one does strengthen, and people who have been through several false alarms are slow to react.
Knowing which sources to trust, and how to read what they say, is one of the most useful everyday skills for living in Grenada. This piece explains who does what in the island's weather information system, how to read the most common forecast products, and how to judge a rumour before passing it on.
The official sources and what each does
Grenada Meteorological Service. Based at Maurice Bishop International Airport and operating under the Grenada Airports Authority, the Met Service began as an aviation weather office and now also issues public forecasts and warnings for Grenada, Carriacou and Petite Martinique. Watches and warnings for tropical storms and hurricanes affecting the state, as well as flash flood and small craft advisories, come from here.
National Disaster Management Agency (NaDMA). NaDMA does not forecast weather. It coordinates the national response: activating emergency operations, announcing which shelters open, and giving instructions about curfews, closures and what to do. When the Met Service issues a warning, NaDMA's messages tell you what that means in practice.
US National Hurricane Center. The NHC in Miami is the regional specialised centre for tropical cyclones in the Atlantic. It names systems, issues track and intensity forecasts and publishes the probability of formation for disturbances. Grenada's Met Service uses this guidance alongside its own analysis when it issues local watches and warnings.
Government Information Service. Official statements from the Prime Minister and government ministries on closures of schools, offices and the airport usually come through GIS, as well as through radio and television.
Radio, TV and online news
Radio remains the backbone of weather communication in Grenada, especially when the power is off and phones are struggling. Stations across the island carry Met Service bulletins and NaDMA updates, and in a serious threat many switch to continuous storm coverage. A battery or wind-up radio, and knowing which stations reach your area clearly, is part of any household's storm kit. Television news and the main local online news outlets carry the same official updates and often publish the full bulletin text.
The strength of local media is that it relays official information quickly and adds local detail: which roads are blocked, which shelters are full, where water is being distributed. Its weakness, particularly online, is that comment sections and shared posts mix in unofficial claims. Treat the official bulletin, quoted in full, as the fact, and the commentary around it as opinion. When outlets quote a named official from the Met Service or NaDMA, that carries far more weight than an unnamed source.
Reading the common forecast products
Much confusion comes from misreading the graphics and terms that get shared. A few basics make them much easier to understand.
- Tropical wave. A trough of low pressure moving west across the Atlantic. Dozens pass through each season, bringing showers and gusty winds. Most never become storms.
- Formation chance. The NHC gives the probability that a disturbance will become a tropical depression or storm within two and seven days. A 20 per cent chance means it probably will not.
- The cone. The forecast cone shows the likely track of the centre, not the size of the storm. Impacts such as heavy rain and wind can extend well beyond the cone, and the centre can end up anywhere inside it.
- Watch versus warning. A tropical storm or hurricane watch means those conditions are possible within about 48 hours. A warning means they are expected within about 36 hours. A warning is the signal to finish preparations.
- Long-range model runs. Single computer model outputs more than five days ahead are often wildly wrong. Professional forecasters look at many runs together and rarely commit to a track that far out.
How to check a rumour before sharing
A minute of checking prevents a lot of panic. These steps work for voice notes, screenshots and forwarded messages alike.
- Ask who the original source is. A named agency, the Met Service, NaDMA or the NHC, is a starting point; an unnamed friend in Trinidad or a weather enthusiast's page is not.
- Check the date. Old storm graphics, including images from Ivan in 2004 or Beryl in 2024, are regularly recirculated as if new.
- Compare with the latest official bulletin. If the claim is not in it, be sceptical.
- Look at the time frame. Anything predicting a direct hit more than five days away is speculation.
- If still unsure, do not forward it. Share the official bulletin instead, or say plainly that the information is unconfirmed.
Using weather apps and WhatsApp wisely
Phone weather apps are useful for planning a beach day or a hike, but most use global models that handle small mountainous islands poorly. They may show rain all day for St George's when it rains for twenty minutes, or forecast clear skies at Grand Etang where it is pouring. Radar and satellite imagery, which some apps and websites show, are more reliable for seeing what is coming in the next hour or two. Satellite loops of the Atlantic show tropical waves approaching days in advance.
WhatsApp and community groups can be genuinely helpful after a storm, for sharing which roads are open, who needs help and where supplies are. Before a storm, they are where rumours spread fastest. A good habit is to agree within family and community groups that only official bulletins are forwarded during a threat, and that local reports are labelled clearly with place and time. Many district disaster committees and community groups now use WhatsApp to share official information, which is useful as long as the source is clear.
Mistakes people make with weather information
Reacting to every wave. Constant alarm wears people out and makes them ignore real warnings. Follow the official formation chance and warnings instead.
Focusing only on the centre line. Grenada can be affected by heavy rain and strong winds even if the centre passes well to the north. Pay attention to the wind field and rainfall forecasts, not just the track.
Ignoring weaker systems. Tropical storms and even waves can cause serious flooding and landslides. Rain, not wind, often causes the most damage in Grenada.
Relying on one source. Power cuts, network outages and overloaded websites happen. Have a radio as well as a phone.
Waiting for the name. Some households only start preparing once a system is named. By then, a storm forming close to the Windward Islands may be less than two days away. Watch the formation chance and act on it.
Forgetting the sea. Swell from distant storms can affect coastal roads and anchorages around Grenada even on sunny days. Small craft and high surf advisories are worth noting if you live, fish or swim along the coast.
A simple routine for the season
Most households manage weather information best with a light, steady routine rather than constant checking. From June to November, glance at the National Hurricane Center outlook once a day; it shows any areas being watched in the Atlantic and their chances of development. If something with a medium or high chance is heading towards the Windward Islands, start listening to Grenada's Met Service bulletins on radio or through local news. Most days, there will be nothing of note and no need to read further.
When a system is within a few days of Grenada, increase the frequency. Advisories come out at regular times through the day, and Grenada's Met Service bulletins translate them into local terms. NaDMA's announcements will say when to finish preparations, which shelters are open and when curfews apply. Keep the radio on during the approach and passage of a storm, and save phone battery for messages that matter. Once the storm has passed, official channels will tell you when roads, ports and the airport reopen.
Frequently asked questions
Who issues hurricane warnings for Grenada?
The Grenada Meteorological Service issues tropical storm and hurricane watches and warnings for Grenada, Carriacou and Petite Martinique, using guidance from the US National Hurricane Center. NaDMA then coordinates the national response and tells people what actions to take.
How far ahead can a hurricane be forecast reliably?
Track forecasts are generally useful about three to five days ahead, with errors growing the further out they go. Intensity is harder to forecast, and storms can strengthen rapidly. Treat anything beyond five days as an early heads-up, not a prediction.
What does it mean when a tropical wave is passing?
It means a trough of low pressure is moving over or near Grenada, usually bringing cloud, showers, gusty winds and sometimes thunderstorms for a day or so. Most waves do not develop further, but some bring heavy rain and flash flooding.
Why do weather apps often get Grenada wrong?
Many apps rely on global models with coarse resolution, which cannot represent the effect of Grenada's mountains on local showers. Rain is often patchy and short-lived, so an app may show rain for hours when it lasts only minutes in a given place.
Should people stop following WhatsApp weather groups?
Not necessarily. They can be helpful for local information after a storm. The key is to check the source, date and time frame of any forecast shared, and to rely on official bulletins for decisions about preparation.
