Adverse weather management

Supporting air traffic in Europe to stay safe, resilient and predictable despite adverse weather

THIS IS PART OF

Optimised operational performance | Network Manager

EUROCONTROL supports the European aviation network in anticipating, coordinating, and mitigating the impact of adverse weather on operations. Working collaboratively with air navigation service providers (ANSPs), airlines, airports, and meteorological service providers, we deliver harmonised weather assessments, proactive planning, and tailored air traffic flow and capacity management (ATFCM) measures to keep the network running safely and efficiently. The network process of managing adverse weather is a structured, collaborative framework integrated into the EUROCONTROL Network Manager’s Air Traffic Flow and Capacity Management (ATFCM) function.

Why it matters

Adverse weather — from thunderstorms and turbulence to low visibility and snow — remains one of the most disruptive factors in air traffic management. It can reduce airport and sector capacity, increase delays, and create ripple effects across the entire network. By managing weather proactively, we help reduce delay, enhance predictability, and support operational decision-making at local and network levels.

	2024		2025
Month	Airports	En-route	Airports	En-route
January	185,123	10,083	359,646	9,539
February	151,369	4,710	113,270	1,917
March	210,953	38,465	213,144	36,191
April	210,620	65,669	145,567	117,606
May	277,710	685,853	215,067	500,469
June	230,557	1,962,742	172,522	1,009,961
July (01-15)	158,015	1,077,012	154,386	692,748
Totals	1,424,347	3,844,534	1,373,602	2,368,431

The EUROCONTROL Network Manager Operations Centre (NMOC) is responsible for the operational planning and coordination from six days before the flight up to the day of operation (D-day). This includes analysing traffic forecasts and airspace availability and preparing pre-tactical plans to optimise airspace usage, all in coordination with air navigation service providers (ANSPs), airlines, and military stakeholders amongst others. Weather specialists embedded in the NMOC work in collaboration with EUMETNET and national MET providers to produce a European weather assessment to help the decision-making process within the NMOC.  Based on this weather assessment the potential impact of adverse weather in combination with traffic demand and capacity together with other events in the network (such as airspace closures, industrial action, runway closures, etc) is assessed and anticipated supporting early and consistent situational awareness for aircraft operators, airports, and area control centres.

EUROCONTROL has introduced specific air traffic flow and capacity management (ATFCM) procedures to help manage adverse weather conditions and capacity shortfalls impacting the European Network. These allow for the adjustment of Calculated Take-Off Times (CTOTs) or tactical re-routes in a way that limits reactionary delay and reduces disruption. Aircraft operators have to submit a flight plan to the EUROCONTROL Network Manager Operations Centre (NMOC) for every flight that will depart from, arrive at or fly over the 42 EUROCONTROL Member States. For Summer 2025 a new procedure in case of severe weather occurrence is also available with the NMOC applying restrictions to some routes through airspace that is set to experience severe adverse weather, effectively reducing the number of aircraft entering this airspace. Based on weather conditions, NMOC select a number of scenarios to reduce the amount of traffic entering into airspace that is forecast to experience poor weather.

Example of applied scenario for a flight from Birmingham to Corfu. The black line shows the initial route, the blue line the alternative route flown avoiding the airspace impacted by bad weather.

These scenarios have been agreed in advance through the Cooperative Decision-Making (CDM) process with air navigation service providers and aircraft operators. As convective weather conditions can have a significant impact on air traffic operations – especially in combination with potentially other disruptions - aircraft operators can also nominate critical flights and ask for help for these from the NMOC to protect their schedule for the day. NMOC also provide rerouting proposals to help airlines avoid the impacted airspace.