Tried the search function and couldn't find much... What should I expect for weather in Northern Zim late April? Rain possible that time of year?

should be very good weather, days will be hot, evenings warm. There should be no rain around.

Thanks. So I should expect it maybe to be similar to September, but much greener?

I was in the Omay at the end of April last year. It rained at least three times, never real hard but plenty enough to get everything wet. If you are leopard or lion hunting your baits will spoil fairly quick.

One morning around May 1st, the weather changed. It cooled down, dried up, and was absolutely perfect.

I only have experience of Zambezi valley first few days of May, but I guess it will be the same or similar.
Very green, occasional shower if the rains have been late. Not too hot during the day and warm at night. You will get a bit of humidity if you have had rain otherwise very pleasant. The weather was perfect for me. The bush will be thick and you can look forward to getting up close and personal. If you are near the Moz border you should still have the ele bulls around that come in to raid the fields.
Have a great time.
Rob