A look at the day ahead in U.S. and global markets from Harry Robertson.

There's only one show in town today: Jerome Powell's mystery monetary tour.

Powell's Federal Reserve is embarking on something of a new era: instead of the strong "forward guidance" that has steered markets in recent years, officials have said they'll become more "data dependent".

If that's the case, the Fed will almost certainly leave rates on hold at 2:00 p.m. ET (1800 GMT), after data on Tuesday showed that inflation cooled to the slowest rate in over two years in May, at 4% year-on-year.

The Fed still has to release its so-called dot plot, which shows where officials think rates are heading. Investors are currently divided about what might happen in July and will read it very closely.

After official hints at a "skip", traders reckon there's about a 63% chance rates rise by 25 basis points again next month, with a 34% chance of a hold, according to CME Group's FedWatch tool.

Could less certainty about rates inject more volatility into markets? The VIX, a gauge of expected S&P 500 volatility, is dozing at its lowest in over three years. Meanwhile, the S&P 500 is at its highest in 14 months.

Investors say a key factor is that markets are still awash with cash, keeping money flowing into riskier assets, although some fear a liquidity crunch is coming.

Markets are typically quiet ahead of the Fed, but could move when U.S. producer price inflation data is released at 8:30 a.m. ET (1230 GMT).

U.S. Treasury yields actually rose on Tuesday after the inflation data, perhaps in a sign of lingering uncertainty about interest rates, although the key 10-year yield is down 4 basis points again this morning.

It's a busy period for investors. After the Fed, it's the turn of the European Central Bank to set rates on Thursday and the Bank of Japan on Friday. The Bank of England goes next week.

Away from central banks, the focus was on former U.S. President Donald Trump, who on Tuesday pleaded not guilty to federal charges that he unlawfully kept classified documents.

Key developments that should provide more direction to U.S. markets later on Wednesday:

* U.S. MBA mortgage application data

* U.S. producer price inflation figures for May

* U.S. Federal Reserve decision

(Reporting by Harry Robertson; Editing by David Evans)