Hurricane watches for Irma are now posted for the northern Leeward Islands. It's still too early to tell whether the U.S. will be affected, but the forecasting models have been progressively moving further west. This does increase the likelihood of a U.S. landfall, although it's still quite possible that the storm could recurve to the northeast and miss the U.S. entirely.
Some good resources:
National Hurricane Center - http://www.nhc.noaa.gov/
Weather Underground "Category 6" blog - https://www.wunderground.com/cat6. Their last Irma post was https://www.wunderground.com/cat6/hurricane-irma-track-towards-lesser-antilles, but this was from yesterday morning. A new post should be up later tonight.
Note: take the comments on Cat6 with a grain of salt. They tend to overreact to every twitch in a model or report, much like daily tracking poll fluctuations around here. 
The various projections for Irma's path resonate badly with this article about Tampa's unpreparedness:
https://www.washingtonpost.com/graphics/2017/health/environment/tampa-bay-climate-change/This is a disaster of epic proportion waiting to happen. Has the US ever been hit by two major hurricanes in the span of a single month before?
