Coastal Convergence - Key Parameters

• Low-level divergence/convergence:
  Convergence in the lowest layers in the atmosphere along or parallel to the coast.
• Low-level omega:
  Rising motion at lower troposphere along or parallel to the coastline.
• Angle of geostrophic wind with the coastline:
  Onshore wind having a relatively small angle with coastline, the lower pressure being on sea, higher pressure over land.
• Accumulated precipitation:
  Signs of enhanced accumulated precipitation within the next 6-24 hours along or parallel to the coastline indicative of coastal effects.

Low-level divergence/convergence

	31 July 2007/00.00 UTC - Meteosat 9 IR 10.8 image; magenta: divergence 1000 hPa

Low-level omega

	31 July 2007/00.00 UTC - Meteosat 9 IR 10.8 image; yellow: omega 925 hPa

Angle of geostrophic wind with the coastline

	31 July 2007/00.00 UTC - Meteosat 9 IR 10.8 image; blue arrows: 10-metre-wind streamlines

Accumulated precipitation

	31 July 2007/00.00 UTC - Meteosat 9 IR 10.8 image; blue: accumulated 12 hour total precipitation (30 July 12 UTC - 31 July 00 UTC)