my experience was different...before you pack up and get out, consider if your home is really in danger
a couple of years ago my neighborhood was given orders to evacuate...nobody did except us, and that was only because we worried about the nearest Hilton being sold out...
our neighborhood was a grid of streets at the base of foothills, and even though we could see flames, there was never any danger that the flames would spread to the neighborhood, the houses were not build into the hillside, residents just stayed in the homes (shelter in place)...really, evacuation was ordered so fire trucks and ambulance would not have traffic to contend with...no one (except us) left after the first order, given at 11am (I asked the cop how long we had to get our stuff together, he did not have a timeframe, so I knew then the order could be discounted)...and then later that evening the police came knocking--our neighbors did not answer the door or just refused the order--no one else left...no punishment resulted
the bad part about leaving is you can't get back in---police set up roadblocks, so if you forget your meds, computers, sex toys your in for difficult nights until the roadblocks are removed
bottom line, you may not want to leave even if ordered, weigh the risks and figure the ulterior motive of the order