The weather and climate of the tropics Part 2 –The subtropical jet streams

Transverse cirrus bands in weather systems: a grand tour of an enduring enigma

“…Galvin (2007) commented that bandlike 'ribbons' may persist in association with the subtropical jet stream for days at a time, an observation consistent with our own experience. However, little research appears to have been done to quantify or explain this characteristic.…”

“…These bands, approximately 15 to 30 kilometres in width, were located along and slightly south of an upper-level jet core over the west coast of Mexico. Whitney et al (1966) used transverse bands as an identifying characteristic of jet streams in TIROS satellite imagery, a relationship that is still widely recognized today (Galvin, 2007). By 1970, however, the research trail grew cold as transverse bands became an increasingly overlooked feature in satellite imagery.…”

The weather and climate of the tropics: Part 5 ‐ Dry environments

“…As stated in Part 2 (Galvin, 2007), severe weather over south-west Asia is not dependent in parts of the Gulf states, as occurred on 20 January 1964 in Bahrain (Deham, personal communication) and rapid temperature falls are characteristic of the change from Suahili to Shamal. On the previous day, the largest fall in maximum air temperature from one day to the next had been recorded at Muharraq (Deham, personal communication).…”

The weather and climate of the tropics Part 4 –Forecasting significant cloud and associated weather

“…The characteristic feature of these disturbances is a large-scale trough in the upper troposphere. Upper troughs are slowmoving, semi-permanent features in the STJ, as discussed in Part 2 (Galvin, 2007). Although large-scale layer clouds on these fronts may be well broken or thin, the development of areas of embedded cumulonimbus within them can be important on their warm side, ahead of the upper trough, in particular in maritime areas.…”