Case: 18 March 2017

Summary

Widespread closed cell conditions over the ENA main site

Description

A multi-day event (March 17th - 18th) having relatively widespread precipitating (drizzle) and closed cell cumulus conditions throughout both days. The low-level winds were modest (10-20 kts) and out of the northeast on March 17th. These winds weakened and shifted easterly by March 18th. The inversion height on March 17th was at approximately 1.7-1.8 km AGL. The stratocumulus deck was likewise associated with a cloud echo top height between 1.5 -2.0 km AGL that gradually lowered with time. This deck was near or below the ambient melting level (potentially, starting closer to 1.7 km AGL, but drifting warmer as the event progressed). SEVIRI observations were suggestive of high clouds building and becoming prominent over the larger Azores regions throughout these event days as associated with an approaching large-scale system.

Available assets

Standard ARM profiling assets, SEVIRI. RLPROF-FEX

Critical period: 04:00-21:00

Closed cell and subcloud precipitation conditions over the ENA main site

Figure 51 True color afternoon MODIS AQUA image with overlaid LES domains. The image domain corresponds to the size of the model forcing domain.