The phrase "mph winds" refers to the speed of the wind. "Mph" stands for miles per hour, which is a measurement used to indicate how fast the wind is blowing. Full definition
The picture above is for 39 + mph winds over the next five days. (alephblog.com)
It is a real miserable storm that gives you a bunch of rain and a 35 mph wind at the same time. (buildingscience.com)
The 140 - mph winds of that storm were excessively damaging and such a hurricane does have the potential to make a repeat performance. (trustedchoice.com)