Forecast

Issue time:


Colour code

   200-2000 microgrammes per cubic metre
   2000-4000 microgrammes per cubic metre
   >4000 microgrammes per cubic metre

Description

Date: 2011-05-29 04:00 UTC
Volcano:
Area:
Source:
Aviation colour code: 
Summit elevation: 
Eruption Details:
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Ash concentration -    Sunday 29 May 2011 04:00 UTC

This data supplements the official Volcanic Ash Advisory Graphics and Volcanic Ash Advisories. The data is to be used with caution. The official Volcanic Ash Graphics and Volcanic Ash Advisories take precedence in all circumstances. Please refer to national NOTAMs for definitive boundaries of no-fly areas.The outer edge of the red zones on these charts approximate the same standard threshold as used in the official Volcanic Ash Advisory Graphics and Volcanic Ash Advisories but due to the automated nature of production will not be identical.
This chart assumes that the volcano will continue to erupt at the same intensity. However, volcanic activity can change at any time and this is not reflected in the chart, and therefore the distribution of ash may change. It does not show where airspace or airports may or may not be open.

Altitiude levels (International Standard Atmosphere)

SFC to FL200 - Ash concentrations between the surface and 20,000 feet.
FL200 to FL350 - Ash concentrations between 20,000 feet and 35,000 feet.
FL350 to FL550 - Ash concentrations between 35,000 feet and 55,000 feet.
SFC to 6000FT - Ash concentrations between the surface and 6,000 feet.

The grey areas represent ash concentrations that are 10 to 20 times the standard (red) threshold representing an ash concentration of 2000 to 4000 microgrammes per cubic metre. To operate in this new zone airlines need to present the CAA with a safety case that includes the agreement of their aircraft and engine manufacturers.
The black areas represent ash concentrations that are 20 times the standard (red) threshold and twice the grey threshold. (concentrations greater than 4000 microgrammes per cubic metre) These are areas within which engine manufacturer tolerances are exceeded.