I've got an old Radio Shack scanner that includes the weather band (162.xxx mhz). I've never brought a radio along on my trips but thought I would give this thing a try next week. So far I haven't heard anything broadcasted and I've had it on for a couple of hours.

How do these things work? Are those freqs just for severe weather or can you get a weather report? Did something happen in the digital switch a few years ago that render this one I have obsolete?

Guys .. no input? I know its an odd question.

Butthead (Ken) I know you know the answer to this. :)

As far as I know the weather service frequencies are as follows:
162.400 MHz 162.500 MHz
162.425 MHz 162.525 MHz
162.450 MHz 162.550 MHz
162.475 MHz

They should all have 24/7 365 broadcasts. Some have special additional information. For instance, along the north shore there are mariners updates.
The newer ones which are Specific Area Message Encoding (SAME) can be programmed to receive only from areas you choose.

If you own a NWR SAME receiver, you will need to program the county you wish to receive watches and warnings for into the radio. It will then alert you only of weather and other emergencies for the county(s) you have programmed. Older (non-SAME) NWR receivers without the SAME capability would alert for emergencies anywhere within the coverage area of the NWR transmitter, typically several counties, even though the emergency could be well away from the listener. The SAME technology can eliminate this appearance of overwarning.

The WX weather radios broadcast on seven frequencies as mentioned above. Their broadcasts are constant, so if you are not hearing them you are not getting them. They broadcast loops of local observations, local forecasts, and severe weather outlook. When there is no severe weather,that is a short segment. When there is severe weather, that can become a lengthy segment.

Current WX radios have a special feature that can alert you if severe weather is in you area - essentially the radio can turn itself on on the middle of the night with a warning. If your older radio does not have this feature, it may not be worth brining on a fall trip. I find WX radios most useful for sever weather in June, July, and August. I worry less about sudden severe weather later in the season. You can get long, lingering storms in the fall, but they usually come in a less surprising way.

you should be able to hear the weather channel. Did you google the directions for your scanner?

Apparently some older weather band radios only pick up 3 frequencies...you mentioned having an older model maybe this is the issue?

NOAA Weather Radio FAQ.

Mr Google knows all. Just punch in the make and model of your scanner and ask for a owners manual. I do it all the time because I forget or loose the manual for a product.