Fortunately not too many, got caught out by a gust front when I was still a student. This front came up so fast, and I had to fight my way back to the field with about 30kph winds and lots of turbulence, aborted the first landing, and made it safely down on 2nd attempt. Instructor took me up straight away for one more circuit which did wonders for my confidence.
Flying in Summer in late morning also brings a tightening of the sphincter muscle sometimes - turbulence is Ok, normally the trike can handle far more than you can. Watch out for winds on the lee side of hills and mountains though.
