The powerful eruption of the Hayli Gubbi volcano in northern Ethiopia continued to cause major disruption to international air traffic on Monday. The latest data from the VAAC (Volcano Ash Advisory Centre) confirms that the ash cloud is spreading over Yemen and Oman and is already affecting key corridors between the Middle East and South Asia. The ash is present at altitudes used by intercontinental flights, with its upper layer reaching 13.5 kilometres.
In its morning advisory, VAAC confirmed the presence of three active ash layers — low, mid, and high — above the regional FIRs, with the highest layer posing the greatest risk to traffic as it is spreading most rapidly to the northeast. The comments in the bulletin noted: “The ash and SO₂ cloud above Yemen and Oman continues to expand toward the northeastern routes. Disruptions are expected to last at least 24 to 36 hours.”
The latest chart clearly shows the current situation (marked in black), as well as projected ash spread for the next six, twelve, and eighteen hours, displayed in green, yellow, and red. The red band illustrates the most dangerous development — high-altitude ash that will in the coming hours extend across the Arabian Sea and move toward southwestern and western India. As it occupies altitudes between roughly 9 and 13 kilometres, it overlaps with nearly all standard cruising levels used by widebody aircraft.
The operational impact is visible directly on the air-traffic map: the skies over Yemen, Oman, and the western Indian Ocean are almost empty, while flights are squeezed into a narrow corridor along southern Saudi Arabia and the Red Sea. A similar picture appears west of India, where traffic is concentrated along the coastline, well clear of the red and orange areas on the chart marking the high and mid-level ash layers.
The European volcanic monitoring service (EUMETSAT Volcanic Ash Service) confirmed that the vertical structure of the cloud corresponds to the colours shown. In its analysis, it stated: “The highest ash levels are rapidly spreading northeast, impacting the busiest international corridors. Avoiding these layers requires major route deviations and significantly increases the load on surrounding airspace.”
Forecasts for +6 and +12 hours show the ash cloud expanding across the Arabian Sea and reaching the approaches to Indian airspace. The +18-hour projection suggests the ash will penetrate deeper into the Indian FIR, potentially triggering further reroutings and additional slowdowns for traffic bound for Delhi, Mumbai, and Hyderabad.
VAAC warns that the volcano continues to show signs of instability and that further ash emissions are possible: “Activity remains variable. Additional high-altitude emissions cannot be ruled out.” Should this occur, aviation authorities expect disruptions to continue over the next two days.
At this moment, air traffic between Europe and South Asia is operating through extremely narrow corridors at the edges of the broad ash cloud. Delays are already visible on flights to India, Pakistan, Sri Lanka, and the southeastern Middle East, and operational adjustments are affecting hundreds of daily flights.
This is one of the largest instances of volcanic interference with air traffic in this region in the past decade, and the further course of events will depend on the stability of the crater and on the direction and strength of upper-level winds, which are currently driving the ash at speeds exceeding 90 km/h.
