In a note to clients — as reported by “Fortune” (http://macte.ch/x7iuB) — Piper Jaffray’s Gene Munster says he expects Apple to report Mac unit sales in the range of 3.6 to 3.7 million for its latest fiscal quarter. Based on data from the NPD Group, the analyst says:

° In the month of March, U.S. Mac sales were up 47% year-over-year, driven by the new MacBook Pros that started shipping in February.

° That 47% uptick followed growth of 20% in January and 12% in February, for average of 27% over the first quarter of 2011. That’s in contrast to the 3.2% drop in worldwide sales reported last week by the IDC research group.

° iPod sales were down 10% year-over-year. Munster expects sales of 9.8 to10.3 million units for Apple’s most recent fiscal year.