The interesting thing about weather is that you can see it coming. That's only partly true with space weather/solar activity. In fact, for some events, we wouldn't have any warning at all as in the case of a high energy burst aimed right at us.
I think the solar weather predictions are models based on trend fitting a bunch of solar parameters like solar flux, sunspots, magnetic field strength, etc.
NOAA has a Space Weather Prediction Center site that includes 45 day prediction of the solar flux index, generally considered a useful indicator of propagation.
That said, NOAA and other national level organizations around the world aren't necessarily focused on HF propagation particularly as there are many other concerns relating to solar weather. The amateur community has stepped up to fill this gap, as you might expect. One
good one can be found here. This one includes a lot of information and educational resources that will help you make sense of the numbers.
There are also a number of PC based programs that will take the numbers and crunch you a forecast for specific bands/times/etc. There is a review of many of them here Review of HF propagation analysis & prediction programs.
Something more immediately useful is: Near-Real-Time MUF Map. Which tells you the current estimated MUF.