Cross-section G-H

ISENTROPES

This cross section is layed through the whole system, cutting aproximately through the center of the low pressure. The right-hand side of the cross-section shows very similar characteristics to the cross-section E-F, because it is cut through the occlusion. The isentropes form typical Y shape and the coldest cloud tops (orange line) are located in the region with the cold-front character. The other part of the occlusion cloud band, to the left of the cross-section, is characterized by a large unstable area, with two minima of potential temperature.

Very prominent feature in this cross-section is the tropopause, folded down to about 300 hPa in the region of the low (behind the cold front).

RELATIVE HUMIDITY

Humidity field is very complex. One maximum is connected to the right hand part of the occlusion cloud band and another, not so pronounced maximum, in the upper layers above the unstable area.

TEMPERATURE ADVECTION

Maximum of cold advection is found behind the cold front part of the occlusion cloud band. Warm advection maximum is much more prominant and is located in the unstable region, connected to the second part of the occlusion cloud band.

WIND SPEED (isotachs)

There are two distinct maxima of wind speed, both at about 250 hPa. The left-hand maximum is found near the left end of the cross-section and is connected to the jet coming from north-northeast, perpendicular to the cold front. The other jet, the onr behind the cold front and the occlusion point comes from south-west and flows parallel to the cold front, to the left of the cloud band. Note how the tropopause is folded between these two jets. This coincides with the low pressure center.

EUMeTrain: VERTICAL CROSS SECTIONS

CROSS-SECTION G-H