15 - 16 MARCH 1998 - 15/21.00 - 16/00.00 UTC - FRONTAL DIAGNOSIS - RELATIVE STREAMS AND CONVEYOR BELTS

by ZAMG

16 March 1998/00.00 UTC - Meteosat IR image; position of vertical cross section indicated	16 March 1998/00.00 UTC - Vertical cross section; black: isentropes (ThetaE), orange thin: IR pixel values, orange thick: WV pixel values

All isentropic surfaces in the area of the low top cloudiness over Greece show sinking in high and middle layers; this will be demonstrated by one example: 300K which is an isentropic surface close to the bottom of the main frontal surface (right image).

16 March 1998/00.00 UTC - Meteosat IR image; magenta: relative streams 300K - system velocity 269° 8 m/s, yellow: isobars

In the image above relative streams very similar to the situations before can be observed (compare 15.00 - 18.00 UTC - Frontal Diagnosis - Relative streams and conveyor belts). There is a limiting streamline at the north-western boundary of the white cloud band between warm rising air from the east and sinking dry air from the north. The relative streams in this westernmost part of the white cloud band are turning and sinking, which might be the reason for decay of cloudiness leading to a sharp cloud boundary there. The sinking of dry air in the area of the low level cloudiness over Greece might be the reason for the restriction of the cloud tops there.

SUB-MENU OF 15 - 16 MARCH 1998

15/21.00 - 16/00.00 UTC - FRONTAL DIAGNOSIS - USE OF VERTICAL CROSS SECTIONS

03.00 - 06.00 UTC - OVERVIEW OF SATELLITE IMAGERY