To me SHTF means a localized break-down of services.
Ice Storms in New England 2 years ago resulted in wide-spread loss of power for an extended period of time (5-10 days) For the first several days many stores in my area were without power, some streets were impassible. Still, most basic services remained operational. Water, Sewer, Gas, police, fire, etc remained mostly operational. It was bady and favored the prepared, but it was not SHTF.
In New England, the most likely events that would result in the S truly Hitting the Fan are major natural disasters (wide spread flooding from a few years back certainly bordered on this in some area where water, power, sewer and gas became unavailable for a week or longer in some places. Or financial break-down.
The later is the one that truely scares me today. The projected budget for 2011 showns 1.6 trillion dollars in borrowing on 2.1 trillion dollars in income with some 800 billion dollars in debt service (payments on debt) and that 800 billion dollars is based on the US having one of the most favorable interest rates in the world. Add to that the fact that many of the states and towns are projecting major budget shortfalls and they are unable to run on debt like the federal government.
There comes a point where these governments need to begin cutting into basic services or raise taxes, either of which can start the spiral that can result in the total break-down of services, and the S hits the fan.
Other senerios that could result in a local break-down of services include: A local outbreak of a dangerous and highly infectious disease that results in a local or regional quarentine to prevent further spread. A terrorist attack on one or more basic services. (New England is more succeptible to this than most like to admit, but I wont share how)
Being prepared for the SHTF possibility total loss of services (Fire, Police, Government, Water, Sewer, Power, Oil/Gas, Financial, etc) to me encompasses preparedness for the lessor, more likely minor emergencies.
Home catched on fire, floods or otherwise becomes unlivable
Extended / Serious Illness and or injury.
Loss of one or two major services for an extended period of time (like losing power for 8 days 2 years ago)
Katrina definately proved localized SHTF events can happen. There was a complete loss of all services in a localized area (yes it was HUGE, but still localized) for an extended period of time.
Fortunately Electromatgnetic Pulse Effect (EMP) on a wide spread area is more myth and legand than reality. Electro-magnetic energy dissipates with the square of range and affects circuits based on their exposed loop area. Automotive Electroncics are routinely subjected to EM fields in excessive of 100W/m or a 400W non-directional transmitter at 1m distance. Generating that same field at 1km takes 4 gigaWatts and the power increases as the cube of the distance, so knocking out the electrical equipment of a city (10km radius) requires trillions of joules of energy.
Most weaponized EMP systems are much more localize, a focuse high-energy EMP attack which burns out sensitive amplifiers in the front end of radar for example, rendering military units nearly blind to attacking forces. Very localized EMP events to temperarily disable the electronics of a few vehicles as an "opening salvo" prior to an attack.
That all said, Power Grids are extremely sensitive to EMP events due to HUGE loop areas. There are strong hypothsese that a significant EMP event could damage key equipment in the power distribution network and cause its failure until substaintial repairs could be made, but it's hardly the mythical "all electrical equipment for miles "burns out"
There has been at least 2 primary Earth Quakes - the first of which was 8.9 - the 5th most powerful on record. The second was 6.6 (seperate fault line). Plus dozens of aftershocks.
As of this morning (US time) there were 4 million power customers without power, and that number was expected to rise
East Coast farmland was heavily hit with tsunami waves, likely destroying its near term crop and potentially damaging its aritability for the next few years.
Hundreds of fires have been recorded, including a nuclear plant's turbine house.
5 Nuclear Ractors at 2 seperate plants lost cooling ability - 1 might have already experienced a melt-down and is leaking radiation (measured 8x normal levels outside the facilty and 1,000x inside)
Hundreds of massive shipping and fishing vessels "parked" on land, Thousands of homes and buildings damaged or destroyed.
Live and learn. But then nobody wants to learn from others. Lets see how this unfolds and what we can learn from it. Feel bad for anyone going through this. But we need to watch and learn from this. Bad guys are not the only ones that can disrupt life.