NWS Ruskin Net Control
Here are three frequencies you should program to hear Skywarn in PASCO County...
Pasco County: 146.670 and 442.650 (146.2 tone both). WA4GDN repeater.
Tampa Bay (Holiday repeater): 443.450 (100.0 tone). NI4CE linked repeater system.
Each county in the Tampa Bay area has a designated frequency for Skywarn activities. However, many use the NI4CE repeater system instead. I assume it's because it has greater coverage, audience and can be directly monitored by the NWS in Ruskin.
I will also concur what jaspence said about the need for Skywarn. I've called in two funnel cloud sightings to the NWS that triggered tornado warnings. Looking at the weather on a computer screen does not replace eyes on the ground. If the NWS didn't see the usefulness of Skywarn spotters, they wouldn't support the program.