Set up conditions on when to activate your evacuation plan. You must have some “set in stone” benchmarks on when to Get Out of Dodge, as well as use of common sense. Below are some examples of disasters that can occur, some likely, some not so. I’ll let you decide which is which. I’ve included some of the signs (or benchmarks) of potential coming events and whether warnings from reliable agencies are available or not.
In most events, I would advise remaining in place. Unless your home is made unlivable, or about to become unlivable, it is the last option to become a refugee. Refugees are at the mercy and whims of anyone one in power. Whether it be Government or gangs, someone will hold power and unless that is you, you will have to do as they say, and get what mercy they give. This is why I recommend one Bug Out Location, Please keep in mind; A BOL does not have to be a spot in the woods with you going ”Rambo”. Families in another state are a perfectly reasonable first choice, provided that you have adequately stocked their location so that you do not become a burden to your family. And at least one fallback location if your BOL is not usable for some reason.
No warning given. Your home is no longer livable, power grid, gas and water down. Societal infrastructure collapse. Roads not usable and emergency services overwhelmed. Might be time to go.
On the other hand, if everything above were still in play, except, your home was still intact, you would have to consider carefully whether or not to evacuate. If you could hold in place for a week or a month would you be better or worse than if you bailed out immediately after the quake?
Inclement Weather (Snow storm, hurricane, tornado)
Warnings are available from weathers services, usually between 2 minutes for tornadoes to 7 days for coastal hurricanes. Evacuation orders are often given 24-48 hours prior to hurricane touchdowns. Ordinarily California doesn’t suffer these problems, but I remember a tornado touching down in Santa Clara a few years ago, and every April/May we get very powerful winds that can rip the roof off of buildings and knock trees into power lines or homes.
Sometimes you get warnings from news services, sometimes they are spontaneous events. Also riots may occur in conjunction with other events compounding the originating problems.
Again, review the Weimar Republic of Germany. A number of indicators are available if you can interpret them correctly. Evacuation may become necessary if you can no longer afford rent or make your house payment. The housing collapse is a prime example of this. I myself lost my home twice. Once because we couldn’t afford it any longer and a second time when my Ex-wife kicked me out, and changed the locks on the doors. Neither one was pleasant, and both cause incredible stress, loss of appetite and sleeplessness. In the second case I lost almost all of my preps and having to start over doing so without a job to support it. I’m sure I will have more to say on this later.
Unless we live in a movie, no warnings are generally available. The impact zone is the only affected area. Anything larger is world shaking if not world ending, so, not much point in talking about it.
Warnings are generally available from NASA, but to date only one instance of any trouble has occurred historically.
Geomagnetic storm and Aurora
The geomagnetic storm causing this event was itself the result of a Coronal Mass Ejection on March 9, 1989. 3.5 Days later, at 2:44 am on March 13, 1989, a severe geomagnetic storm struck Earth. The storm began on Earth with extremely intense auroras at the poles. The aurora could be seen as far south as Texas. As this occurred during the cold war, many worried that a nuclear first-strike might be in progress. Others considered the intense auroras to be associated with the Space Shuttle mission STS-29, which had been launched on March 13 at 9:57:00 AM. The burst caused short-wave radio interference, including the jamming of radio signals from Radio Free Europe into Russia. It was thought that the signals had been jammed by the Soviet government.
As midnight came and went, invisible electromagnetic forces were staging their own pitched battle in a vast arena bounded by the sky above and the rocky subterranean reaches of the Earth. A river of charged particles and electrons in the ionosphere flowed from west to east, inducing powerful electrical currents in the ground that surged into many natural nooks and crannies.
Some satellites in polar orbits lost control for several hours. GOES weather satellite communications were interrupted causing weather images to be lost. NASA's TDRS-1 communication satellite recorded over 250 anomalies caused by the increased particles flowing into its sensitive electronics. The Space Shuttle Discovery was having its own mysterious problems. A sensor on one of the tanks supplying hydrogen to a fuel cell was showing unusually high pressure readings on March 13. The problem went away just as mysteriously after the solar storm subsided.
The variations in the earth's magnetic field also tripped circuit breakers on Hydro-Québec's power grid. The utility's very long transmission lines and the fact that most of Quebec sits on a large rock shield prevented current flowing through the earth, finding a less resistant path along the 735 kV power lines.
The James Bay network went offline in less than 90 seconds, giving Quebec its second massive blackout in 11 months. The power failure lasted 9 hours and forced the company to implement various mitigation strategies, including raising the trip level, installing series compensation on ultra high voltage lines and upgrading various monitoring and operational procedures. Other utilities in North America, the UK, Northern Europe and elsewhere implemented programs to reduce the risks associated with geomagnetically induced currents.
In August 1989, another storm affected microchips, leading to a halt of all trading on Toronto's stock market.
Since 1995, geomagnetic storms and solar flares have been monitored from the Solar and Heliospheric Observatory (SOHO) joint-NASA-European Space Agency satellite..
WWIII (Go Wolverines) and Terrorist Attack
I wasn’t in NY during 9/11 and no one I know was either, but lots of people were in the air that day, and when they grounded all aircraft, all those passengers had, was what they packed. Forgot about them, didn’t you? If someone was going to a destination they were probably better off as they were fresher, had more cash on hand, their packed clothes were probably clean, etc. If they were coming back from somewhere, unless they were a survivalist/prepper, you can be sure most were in a world of hurt.
There is no warning of an impending attack, or loose rumors from DHS about "chatter". Bad guys are just suddenly there doing bad things.