Update
I did some research and in trying to find the easiest and cheapest solution to my problem have narrowed down the options to two
The first option is johnd's suggestion of purchasing a 6544. Because I already have a WeatherlinkIP plugged into the port in the battery compartment of my console, it seem I will also have to purchase an Envoy (6316). It does appear that I will be able to program the device for both wind speed and direction which I like. Cost is about $250
The second option is galfert's very detailed and thorough recommendation of going with Meteobridge and Samsung Smarththings devices. I'm not sure I could program this setup to switch on the pump for both wind speed and direction. Cost is about $300
If previous posters would please comment on the pros and cons of both of these options I would be very grateful. In fact I already am grateful to this community of experts. Thank you!
Both of those options seem like an awful lot of money to spend, though the SmartThings approach would give you a setup that you could add more capabilities to at relatively small incremental costs. My VP 2+ is hooked up (currently via a USB logger) to a Raspberry Pi, running weewx. If I wanted to do what you want to do, I would probably use weewx's alarm capability to toggle one of the Pi's I/O pins and hook this up to appropriate circuitry to switch the pump. My additional hardware cost would be between 0 and $20, depending on what sort of pump it is (12 V DC, mains, whatever). Even starting from where you are and needing to buy the Pi and the USB logger, the hardware cost would probably not be more than half of that of your first approach.
But (and it is a big but) I have enough experience with programming and Pis that I would not anticipate the software side being a problem. If you want a 'plug and play' solution and/or are not somewhat comfortable with Unix and/or Python programming, my approach would not work for you. Whether this approach makes any sense at all for you, therefore, depends critically on your level of comfort in this realm.