METEOSAT SECOND GENERATION (MSG) NIGHT-TIME CONVECTION APPLICATIONS OF METEOSAT SECOND GENERATION (MSG) NIGHT-TIME CONVECTION Author: Jochen Kerkmann (EUMETSAT) (kerkmann@eumetsat.de) Contributors: A. Canessa (Meteo AM)

MSG SEVIRI CHANNELS USEFUL TO MONITOR CONVECTION PART 1: MSG SEVIRI CHANNELS USEFUL TO MONITOR CONVECTION NIGHT-TIME

Recommended Channels WV6.2 upper-level moisture WV7.3 mid-level moisture, early convection IR10.8 top temperature

IR10.8 Top Temperature Click on the icon to see the animation (02:00-08:45 UTC, AVI, 6155 KB) ! Squall Line over Western Africa causing violent rainfall and sandstorms MSG-1, 14 July 2003, 02:00 UTC, IR10.8

CHANNEL DIFFERENCES USEFUL TO MONITOR CONVECTION PART 2: CHANNEL DIFFERENCES USEFUL TO MONITOR CONVECTION NIGHT-TIME

Recommended Differences IR3.9 - IR10.8 particle size, phase IR8.7 - IR10.8 optical thickness IR12.0 - IR10.8 optical thickness WV6.2 - IR10.8 overshooting tops WV6.2 - WV7.3 overshooting tops

RED-GREEN-BLUE (RGB) COLOUR COMPOSITES FOR MONITORING CONVECTION PART 3: RECOMMENDED RED-GREEN-BLUE (RGB) COLOUR COMPOSITES FOR MONITORING CONVECTION NIGHT-TIME

Recommended RGBs Night-time Red: Cloud optical depth, approximated by the 12.0 - 10.8 mm or 10.8 - 8.7 brightness temperature. Green: Cloud particle size and phase, approximated by the 10.8 - 3.9 mm brightness temperature. Blue: Temperature, provided by 10.8 mm brightness temperature.

Typical Convective Development - Nighttime - 12.0-10.8 10.8-8.7 10.8-3.9 10.8 I. Very early stage white white white light grey (low, warm water cloud) opt thick opt thick low water warm II. First convection* white white light grey dark grey (first convective towers) opt thick supercooled supercooled cold water water III. First icing white grey b/w noise black (transformation in Cb) opt thick ice cloud very cold very cold IV. Large icing white grey b/w noise black (Cb anvils) opt thick ice cloud very cold very cold *This phase is more frequent in Africa, i.e. it is more easy to find examples for this phase in tropical convection

RGB 10-09 / 09-04 / 09 Red Green Blue 12.0-10.8 10.8-3.9 10.8 RGB I. Very early stage 255 255 200 white-light yellow II. First convection 255 200 100 light brown III. First icing 255 100/255 0 red-yellow IV. Large icing 255 100/255 0 red-yellow

5 8 9 3 7 4 MSG-1 11 November 2003 03:00 UTC RGB Composite 1. Desert quartz sands. 2. Desert soil. 3. Sea surface. 4. Sc with small drops. 5. Supercooled water layer clouds, no precip. 6. Lightly precip. cu. 7. Cb with lightning. 8. Deep convection, growing zone. 9. Deep convection, dissipation zone. 10. Thick cirrus. 11. Thin cirrus. 5 8 9 3:13 3 7 4 MSG-1 11 November 2003 03:00 UTC RGB Composite R = IR12.0-IR10.8 G = IR10.8-IR3.9 B = IR10.8 6 5 5 11 2 1 2 10 1

MSG-1 23 April 2003 19:00 UTC RGB Composite R = IR12.0-IR10.8 G = IR10.8-IR3.9 B = IR10.8

MSG-1 8 June 2003 19:30 UTC RGB Composite R = IR12.0-IR10.8 G = IR10.8-IR3.9 B = IR10.8

PART 4: EUROPEAN EXAMPLES

Severe Hailstorm Padova-Treviso (I) 28 August 2003

MSG-1, 28 August 2003, RGB Composite 16:30 UTC 17:30 UTC MSG-1, 28 August 2003, RGB Composite R=IR12.0-IR10.8, G=IR10.8-IR3.9, B=IR10.8

MSG-1 28 August 2003 17:30 UTC RGB Composite R = IR12.0-IR10.8 G = IR10.8-IR3.9 B = IR10.8

PART 5: AFRICAN EXAMPLES

Convection Ghana 23 April 2003

Thin Cirrus MSG-1 23 April 2003 19:00 UTC Severe Convection Channel 09 BT [K]

Click on the icon to see the animation (19:00 - 20:30 UTC, AVI, 8539 KB) ! MSG-1 23 April 2003 19:00 UTC Channel 09 (IR10.8)

MSG-1 23 April 2003 19:00 UTC Difference Image IR3.9 - IR10.8

MSG-1 23 April 2003 19:00 UTC Difference Image IR8.7 - IR10.8

MSG-1 23 April 2003 19:00 UTC Difference Image IR12.0 - IR10.8

MSG-1 23 April 2003 19:00 UTC RGB Composite R = IR12.0-IR10.8 G = (IR3.9-IR10.8)i B = IR10.8

MSG-1 23 April 2003 19:00 UTC RGB Composite R = IR10.8-IR8.7 G = (IR3.9-IR10.8)i B = IR10.8

MSG-1 23 April 2003 19:00 UTC RGB Composite R = IR3.9-IR10.8 G = IR8.7-IR10.8 B = IR12.0-IR10.8