WINTER FOG EXPERIMENT (WiFEX)

CURRENT CONTEXT: WiFEX has completed 10 successful years since its launch in 2015 to study dense winter fog over North India.

ABOUT WiFEX:

• Launch: Winter 2015 at Indira Gandhi International Airport, New Delhi.
• Lead Institution: Indian Institute of Tropical Meteorology (IITM), under Ministry of Earth Sciences.
• Collaborators: India Meteorological Department (IMD), National Centre for Medium Range Weather Forecasting (NCMRWF).
• Focus: One of the world’s few long-term open-field experiments solely dedicated to winter fog.

OBJECTIVES:

• To improve nowcasting (within 6 hours) and forecasting of winter fog.
• To reduce the adverse impacts of fog on aviation, transport, economy, and human life.

HOW IT WAS CONDUCTED:

• Used instruments like micrometeorology towers, ceilometers, high-frequency sensors.
• Collected data on temperature, humidity, wind, turbulence, soil heat, and aerosols.

 KEY OUTCOME:

• Developed a high-resolution (3 km) probabilistic fog prediction model.
• Model achieves over 85% accuracy for predicting very dense fog (visibility <200m).

What is Dense Winter Fog?

Dense winter fog refers to a weather condition where air contains a large amount of suspended water droplets, drastically reducing visibility—often to less than 200 meters. It is common during winter months (December–February), especially in North Indian plains.