Fuji Abound
29th May 2006, 17:57
Ever since I was a kid the weather has fascinated me. I remember watching the vultures soaring in the sea breeze as it hit the coast. I also remember my first instructor telling me the only part of his ATPL he enjoyed was met.
Today I was off to Bristol. The TAF was not that attractive. I have done my share of dodging round the more active Cbs when I must. However the forecast of hail was not encouraging and the weather radar suggested the storm cells might be quite closely packed and relatively slow moving. In the end as I didn’t really need to go the aircraft stayed wrapped up in its hangar.
So I sat in the hot tub with a very good bottle of wine.
So what is the point.
Well, I was fascinated to watch a few storm cells come and go. On each occasion it was noticeable how active the swifts became as the cell approached. Before there were few if any. They were active at heights up to maybe 5,000 feet or so. I have always found heights difficult to judge from the ground. Every time just a few minutes before the rain came they disappeared - completely. On two occasions almost as soon as it started raining it turned to hail - quite large hail as it turned out. The wind came before and during the heaviest rain and then almost completely subsided. The swifts never returned until the front of the next storm cell.
So what was going on.
The swifts I guess were attracted by the rising air ahead of the cell. Presumably this provided a good supply of insects. The rising air was sufficient to cause the formation of hail which fell as the center of the cell passed, accompanied by the localised microburst of air flowing towards the ground and “padding” out.
Now here is the bit I don’t understand. Looking up my old Oxford IR met training module the classic storm cell is depicted with the air rising in a central cone surrounded by downdrafts “padding” out as they contact the ground. In fact on each occasion that only appeared to happen on the “windward” front of the cell, never on the leeward edge. So what exactly is going on with the cone theory and when and how would you expect downdrafts on both the windward and leeward edges of the cell?
Today I was off to Bristol. The TAF was not that attractive. I have done my share of dodging round the more active Cbs when I must. However the forecast of hail was not encouraging and the weather radar suggested the storm cells might be quite closely packed and relatively slow moving. In the end as I didn’t really need to go the aircraft stayed wrapped up in its hangar.
So I sat in the hot tub with a very good bottle of wine.
So what is the point.
Well, I was fascinated to watch a few storm cells come and go. On each occasion it was noticeable how active the swifts became as the cell approached. Before there were few if any. They were active at heights up to maybe 5,000 feet or so. I have always found heights difficult to judge from the ground. Every time just a few minutes before the rain came they disappeared - completely. On two occasions almost as soon as it started raining it turned to hail - quite large hail as it turned out. The wind came before and during the heaviest rain and then almost completely subsided. The swifts never returned until the front of the next storm cell.
So what was going on.
The swifts I guess were attracted by the rising air ahead of the cell. Presumably this provided a good supply of insects. The rising air was sufficient to cause the formation of hail which fell as the center of the cell passed, accompanied by the localised microburst of air flowing towards the ground and “padding” out.
Now here is the bit I don’t understand. Looking up my old Oxford IR met training module the classic storm cell is depicted with the air rising in a central cone surrounded by downdrafts “padding” out as they contact the ground. In fact on each occasion that only appeared to happen on the “windward” front of the cell, never on the leeward edge. So what exactly is going on with the cone theory and when and how would you expect downdrafts on both the windward and leeward edges of the cell?