Some have speculated that something must have been wrong before the weather penatration for the crew to continue through the area. As said before it may not have been a bad course to take with the information available. With a loss or discrepency in airspeed indications, manual flight, the situation could go pear-shaped in a matter of minutes or less. If the ISIS was also affected this is a grave scenario especially in poor weather and nighttime. It would be beyond the capability of most of us I belive.