Behind the Forecast: How Morocco Predicts the Weather

When you check the weather forecast for Marrakech or Casablanca, a chain of technology, science, and human expertise has already been at work for hours. Satellites have scanned the atmosphere from 36,000 km above. Weather stations have transmitted temperature, pressure, and wind data every ten minutes. Supercomputers have crunched billions of calculations. And trained forecasters have interpreted the results, adding local knowledge that no algorithm yet matches. Morocco's weather forecasting system is more sophisticated than most people realize, and it is evolving rapidly as new technologies, from GPS meteorology to machine learning, reshape what is possible.

The Direction Generale de la Meteorologie (DGM)

At the center of Morocco's weather enterprise is the Direction Generale de la Meteorologie, known universally as the DGM. Established in 1961, shortly after Morocco's independence, the DGM is the national meteorological service responsible for weather observation, forecasting, and climate monitoring across the kingdom.

Mission and Mandate

The DGM's mandate extends well beyond providing daily forecasts. Its responsibilities include:

• Public weather forecasting: Issuing daily forecasts, severe weather warnings, and seasonal outlooks for the general public.
• Aviation meteorology: Providing specialized forecasts and real-time weather information for Morocco's airports, a critical function given the country's position on major international flight routes.
• Marine meteorology: Forecasting sea conditions, wave heights, and coastal weather for the fishing fleet, shipping, and port operations.
• Agricultural meteorology: Providing tailored forecasts and advisories for the agricultural sector, including frost warnings, irrigation guidance, and harvest weather outlooks.
• Climate monitoring: Maintaining long-term climate records, tracking climate trends, and contributing to international climate assessments.
• Research: Conducting and supporting research into atmospheric science, climate change, and forecasting methodology.

Organizational Structure

The DGM is headquartered in Casablanca and operates through a network of regional directorates that cover the entire country. Each regional directorate is staffed with trained meteorologists who produce localized forecasts and maintain observing stations within their territory.

The regional structure is important because Morocco's climatic diversity demands local expertise. A forecaster in Tangier needs deep knowledge of Mediterranean frontal systems and the Levante wind. A forecaster in Ouarzazate must understand desert convection and Atlas foehn effects. This decentralized expertise, combined with centralized numerical modeling, is the strength of Morocco's forecasting system.

The Observation Network

Accurate forecasting begins with accurate observation. Morocco maintains an extensive network of weather observation systems that feed data into forecasting models.

Surface Weather Stations

Morocco operates over 400 surface weather stations distributed across the country. These stations measure the fundamental atmospheric variables.

• Temperature: Measured in standardized Stevenson screen enclosures at 1.5 meters above ground level.
• Humidity: Measured by electronic hygrometers, providing relative and absolute humidity.
• Atmospheric pressure: Measured by precision barometers, with data corrected to mean sea level for comparability.
• Wind speed and direction: Measured by anemometers and wind vanes at 10 meters above ground level.
• Precipitation: Measured by rain gauges, both manual (read daily) and automatic (providing real-time data).
• Solar radiation: Measured at specialized stations, providing data essential for solar energy planning and agricultural modeling.

The network density varies. Urban areas, airports, and agriculturally important regions have dense coverage. Remote mountain and desert areas have sparser coverage, creating gaps that can affect forecast accuracy in these regions.

Automatic Weather Stations (AWS)

Morocco has progressively modernized its network with automatic weather stations that transmit data in real time via satellite or cellular networks. These stations operate continuously, providing observations every ten minutes rather than the three-hourly or six-hourly intervals of traditional manual stations.

The AWS network is particularly valuable for severe weather monitoring, where conditions can change rapidly. A sudden pressure drop, wind shift, or temperature spike can signal an approaching storm, and the earlier this is detected, the more warning time is available.

Upper-Air Observations

Surface observations tell only part of the story. The atmosphere is three-dimensional, and forecasting requires knowledge of conditions at all levels.

• Radiosondes: Morocco launches weather balloons (radiosondes) from several stations twice daily, at the internationally coordinated times of 00:00 and 12:00 UTC. These instruments ascend to altitudes of 20 to 30 km, measuring temperature, humidity, pressure, and wind speed and direction throughout the atmospheric column. The data is transmitted in real time and shared with the global meteorological community through the WMO's Global Telecommunication System.
• Pilot balloons: Simpler than radiosondes, pilot balloons are tracked visually or by radar to measure upper-level winds.

Weather Radar

Morocco operates a network of weather radar installations that provide real-time imagery of precipitation patterns. Radar is invaluable for monitoring and tracking rain systems, thunderstorms, and the mesoscale convective systems that produce flash floods.

The radar network covers most of the populated areas of Morocco, though gaps remain in the deep south and some mountain regions. Each radar scans a radius of approximately 200 to 250 km, updating every five to ten minutes. The data is composited into national mosaics that forecasters use to track the movement and intensification of weather systems.

Satellite Imagery

Morocco benefits from several satellite systems that provide continuous imagery of the atmosphere.

• Meteosat (operated by EUMETSAT): Geostationary satellites positioned over the equator at 0 degrees longitude provide imagery every 15 minutes in visible, infrared, and water vapor channels. These images show cloud patterns, sea surface temperatures, dust plumes, and atmospheric moisture distributions across the entire Morocco-Atlantic region.
• Polar-orbiting satellites (including NOAA, MetOp, and Suomi NPP): These satellites pass over Morocco several times daily, providing higher-resolution imagery and specialized atmospheric soundings.
• Sentinel satellites (Copernicus program): European Earth observation satellites provide data on land surface temperature, vegetation health, and atmospheric composition that support climate monitoring and agricultural forecasting.

GPS Meteorology: A New Frontier

One of the most innovative developments in Morocco's observational capability is the use of GPS (Global Positioning System) signals for atmospheric measurement.

How It Works

GPS satellites transmit signals that pass through the atmosphere before reaching ground-based receivers. The atmosphere, specifically its water vapor content, delays and bends these signals in measurable ways. By analyzing the delay of GPS signals arriving at a ground station, meteorologists can calculate the total column of water vapor in the atmosphere above that station.

Morocco's GPS Meteorology Network

Morocco has deployed a network of high-precision GPS receivers at strategic locations across the country. These receivers, originally installed for geodetic (land surveying) purposes, have been adapted for meteorological use. The data they provide is particularly valuable because:

• Continuous measurement: GPS receivers operate 24/7, providing water vapor estimates every 30 minutes.
• All-weather capability: Unlike some satellite measurements, GPS signals are not blocked by clouds, making the technique useful in exactly the conditions (overcast, rainy) where additional data is most needed.
• Complementarity: GPS water vapor data fills gaps between radiosonde launches (which occur only twice daily) and provides a check on satellite-derived moisture estimates.

Applications

GPS-derived water vapor data is used to:

• Improve the initialization of numerical weather prediction models, leading to more accurate forecasts.
• Monitor the approach of moisture-laden air masses that may produce heavy rainfall.
• Validate satellite-derived moisture products.
• Study long-term trends in atmospheric moisture as part of climate change research.

Numerical Weather Prediction: The Computer Models

The core of modern weather forecasting is numerical weather prediction (NWP), which uses mathematical models of the atmosphere to simulate future weather conditions.

Global Models

Morocco uses output from several global NWP models, including:

• ECMWF (European Centre for Medium-Range Weather Forecasts): Widely considered the world's leading global model, the ECMWF's Integrated Forecasting System provides forecasts out to 15 days with a horizontal resolution of approximately 9 km. Morocco, as a member of ECMWF's cooperation agreements, has access to this data.
• GFS (Global Forecast System): The American global model, freely available and widely used as a complement to ECMWF.
• ARPEGE: The French global model, developed by Meteo-France, with which the DGM has a long-standing partnership.

Regional Models

Global models, while powerful, have limited resolution and may not capture the fine-scale terrain effects that dominate Morocco's weather. To address this, the DGM runs regional models at higher resolution.

• AROME: A high-resolution model (approximately 2.5 km grid spacing) that can explicitly resolve convective storms, mountain effects, and sea breezes. AROME is particularly valuable for forecasting flash-flood-producing thunderstorms in the Atlas and Rif regions.
• ALADIN: A regional model with intermediate resolution (approximately 7 km) that provides a bridge between global and convection-resolving scales.

These regional models are "nested" within the global models, using global model output as boundary conditions while resolving finer-scale features within Morocco.

Machine Learning: The Next Revolution

Morocco's DGM, in partnership with academic institutions and international organizations, is exploring the application of machine learning (ML) and artificial intelligence (AI) to weather forecasting.

Current Applications

• Post-processing: ML algorithms are used to correct systematic biases in NWP model output. For example, a model might consistently overestimate temperature in Marrakech by 1.5 C during summer. An ML algorithm trained on historical model errors can automatically apply this correction, improving forecast accuracy.
• Nowcasting: For very short-range forecasts (0 to 6 hours), ML techniques that analyze radar imagery, satellite data, and surface observations can predict the evolution of precipitation systems faster and sometimes more accurately than traditional NWP models.
• Severe weather classification: ML classifiers can identify atmospheric patterns associated with severe weather events (heatwaves, flash floods, strong winds) from model output, helping forecasters focus attention on the highest-risk periods.

Future Directions

• Deep learning for precipitation: Convolutional neural networks and other deep learning architectures are being tested for rainfall prediction, a notoriously difficult task for traditional NWP models in semi-arid regions.
• Ensemble interpretation: ML techniques can synthesize information from multiple model runs (ensembles) to produce probabilistic forecasts that communicate uncertainty more effectively.
• Renewable energy forecasting: As Morocco expands its solar and wind energy capacity, accurate forecasting of solar radiation and wind speed becomes economically critical. ML models trained on historical weather and energy production data can optimize renewable energy scheduling.

The Regional Directorates: Local Expertise

The DGM's regional directorates are the front line of Moroccan weather forecasting. Each directorate covers a specific geographic zone and is staffed with forecasters who combine model output with deep local knowledge.

Why Local Knowledge Matters

Models are powerful but imperfect. They may not capture:

• Terrain effects below the model's resolution, such as the channeling of wind through a specific mountain pass or the fog-producing effect of a particular coastal headland.
• Microclimates like Essaouira's anomalous coolness or the extreme heat trap of the Fes basin.
• Historical patterns that experienced forecasters recognize intuitively: "When the wind shifts to the northeast in Tangier with this pressure pattern, it always means rain within 12 hours."

Regional forecasters add this knowledge to the model guidance, producing forecasts that are more accurate and more relevant to local users than raw model output alone.

Key Regional Directorates

• Casablanca: Covers the economic capital and the busiest airport. Specializes in coastal weather, fog, and urban heat island effects.
• Marrakech: Covers the Haouz plain and northern High Atlas. Focuses on extreme heat events, Atlas snowfall, and Chergui wind prediction.
• Tangier: Covers the Strait of Gibraltar region. Specializes in maritime weather, Levante wind events, and Mediterranean frontal systems.
• Agadir: Covers the Souss-Massa and southern coast. Focuses on coastal upwelling, fog, and the interaction of Saharan and oceanic air masses.
• Oujda: Covers the Oriental region. Specializes in continental weather patterns and interaction with Algerian air masses.

Communicating the Forecast

Producing an accurate forecast is only half the challenge. The other half is communicating it effectively to the public.

Communication Channels

• DGM website and mobile app: The primary digital channels, providing forecasts, warnings, radar imagery, and satellite data.
• Social media: The DGM maintains active presence on social platforms, sharing forecasts, warnings, and educational content.
• Traditional media: Television and radio remain critical channels, especially for reaching rural populations without reliable internet access. The DGM provides regular bulletins to national broadcasters.
• Aviation and marine channels: Specialized forecasts are disseminated through international aviation and maritime communication systems.

Warning System

The DGM operates a four-level warning system:

• Green: Normal conditions. No particular risk.
• Yellow: Potential for unusual weather. Stay informed.
• Orange: Significant weather expected. Take precautions.
• Red: Dangerous weather imminent or occurring. Take immediate action.

Warnings are issued for specific hazards: heavy rain, strong wind, extreme heat, extreme cold, snowfall, sandstorm, and high seas. Each warning specifies the affected region, the expected timing, and recommended actions.

Challenges and Future Development

Coverage Gaps

Despite significant investment, Morocco's observation network has gaps, particularly in remote mountain and desert areas. Expanding coverage with additional automatic stations, radar installations, and mobile observation platforms is a priority.

Human Capacity

Training the next generation of meteorologists is essential. The DGM operates a training center and partners with international institutions, but the rapid pace of technological change demands continuous professional development.

Climate Services

Beyond weather forecasting, there is growing demand for climate services: seasonal outlooks, climate change projections, and sector-specific advisories for agriculture, water management, energy, and health. Developing these services requires investment in climate modeling, data management, and interdisciplinary collaboration.

International Cooperation

Morocco's weather does not respect borders. Effective forecasting requires cooperation with neighboring countries (Algeria, Mauritania, Spain), regional organizations (EUMETSAT, ACMAD), and global bodies (WMO, ECMWF). Morocco is an active participant in these networks, sharing data and contributing to international forecasting efforts.

Conclusion

The weather forecast on your phone is the visible tip of an enormous iceberg. Beneath it lies a national infrastructure of observation stations, radar networks, satellite receivers, supercomputers, machine learning algorithms, and trained human experts working around the clock. Morocco's DGM has built a forecasting system that rivals many developed-country services, and it continues to invest in the technology and expertise needed to keep pace with a changing climate. The next time you check the forecast for Marrakech or Casablanca, appreciate the science, technology, and human dedication that made it possible.