Is it possible to wipe SSD with strong magnetic force?

Flash memory uses floating gate transistors to store data, rather than the magnetic method used by hard disks. The presence of a magnetic field is not necessarily a problem for an SSD, but the rate of change of magnetic flux could cause damage:

CFs [Compact Flash drives] aren't magnetic media, so they can't be erased like, say, a floppy disk or a hard drive. However, depending on the strength of the magnetic field, a CF isn't completely safe. For instance, if you were to do an MRI of your CF (or any other piece of sensitive electronic circuitry, for that matter), it would be toast. It's not simply the strength of the magnetic field that matters, so much as the rate at which the field changes. If you go from strong field to no field very quickly or vice versa, then the change in magnetic flux can generate small voltages over wires, traces, etc. If the voltages are high enough, then they can cause damage. I don't know, practically, in the real world, what sources of magnetic fields might pose a danger to a CF -- or a camera -- or a lens.

I was just exploring this in my science class the other day (my friend and I had finished early so we had a good 15 minutes or so to muck around with what the teacher called super magnets) and I can safely say that it depends what you do with the magnet, the strength of said magnet, and on the USB stick itself. If you simply leave the magnet sitting on top of the usb, they will be attracted but the USB won't be wiped. If, however, you swipe the magnet over the USB many times in rapid succession, then you may wipe it, and depending on the speed and strength of the magnet you could also render the USB unformattable. My friend's USB was renered completely and utterly useless after this experience, while mine (which was put in pretty much the same kind of conditions) was perfectly fine, even after I threw it at the fan a few times (don't ask haha). Now, I have a magnetic USB! It even manages to stick to the fridge, supported by nothing but it's magnetic powers. But it still works. By the way, my USB is a $10 Kodak 8 GB which I bought from target, but my friend's was a $20 USB from a very reputable computer shop. So money doesn't always matter.

P.S My friend's USB broke when I threw it at the fan :P

No, because flash memory devices do not use magnetism to store data the way hard drives do. For example, SanDisk SD cards are rated to withstand static (not changing) magnetic fields of up to 5000 gauss.

However, as sblair noted, sufficiently strong, changing magnetic fields can damage any electronic equipment, including flash memory devices. This is due to electromagnetic induction producing electrical currents inside the circuitry that are strong enough to damage the hardware.

For reference, according to Wikipedia, an MRI scanner can generate magnetic fields ranging from 600 to 70000 gauss, depending on the model and operating mode, while a typical refrigerator magnet generates about 50 gauss. Note that MRI scanners generate changing magnetic fields which can easily damage most electronic equipment. However, unless you're moving a strong magnet at high speeds (such as by rapidly rotating it), normal, everyday magnetic objects will not damage an SSD or other flash memory device. Also, you can use a Faraday cage to protect devices against electromagnetic induction.