engine hesitation

My 1996 Jimmy 4.3L 4wd seems to hesitate while crusing at around 45 mph. The check engine light starts to flash and the car seems as if it's going to stall. This lasts for 30 seconds and then it stops. I just had A new block put in about a year ago. If it helps it was snowing.

do i get this right stalling and snowing?