Altocumulus has a puffy, patchy, or roll-like texture.
Such a cloud formation, either
Altocumulus Castellanus or
Altocumulus of a chaotic sky, are both described as precursors of thundery weather.
Although there's clear blue sky with a few bands of
altocumulus, the sky to the north looks like a sea of towering cumulus.
Daytime heat with
altocumulus is expected throughout, showery prospects loom briefly in the Kavango by midweek.
Though a roll cloud may not be seen, strong chinooks are often accompanied by spectacular multiple-layered standing lenticular clouds ("
altocumulus standing lenticular" or ACSL) and a chinook arch, a broad mid-level
altocumulus or cirrus cloud extending leeward from the mountains.
From Sunday into Monday for example, the upper air extensions drew some moisture towards these distant vortex cores, an
Altocumulus cloud-band was the factual evidence.
The presence of
altocumulus cloud identifies this tropical air source in no uncertain fashion.
This gentle advection was best seen in the middle cloud at
altocumulus level.
The remarkable wind-flow patterns across the Atlantic provided an airflow switch-back flowing from mid-Amazon and into southern Africa, the cirrus and very high-based
altocumulus bands of the early and mid-week exemplified this.
Such air cools as it travels southward and ability to form thicker
altocumulus is to be expected.
This weekend sees the surface ridge extend to the Cape and along the coast while, on its northern side (west of the Walvis latitude) an upper air cut-off pattern develops from 700mb through the
altocumulus levels to even 300mb (hPa), persisting until mid-week before amalgamating with a new frontal trough nearing the Cape by Wednesday.
The current
altocumulus patterns reveal the least turbulent levels seen for many weeks now.