NEW YORK (CNN/Money) - A deluge of details about corporate America's bleak summer is expected to flood the market in the weeks ahead as companies offer early looks at their September quarters.

So far, of the 211 companies in the Standard & Poor's 500 index issuing third-quarter pre-announcements, 108 have warned on results while 46 have said their numbers will top forecasts. Fifty-seven firms told investors they will meet Wall Street's financial targets, according to First Call.

But First Call, which tracks earnings, said the ratio of warnings to upside surprises has been growing as the third quarter draws to a close, raising the likelihood of more bad news in the weeks ahead.

"That's ominous because we've seen the ratio come down in recent quarters," Chuck Hill, First Call's director of research, told CNNfn's Market Call.

As if on cue, EDS (EDS: Research, Estimates), the computer services company, late Wednesday prepared investors for a major third-quarter shortfall, a day after J.P. Morgan Chase (JPM: Research, Estimates) issued a warning of its own.

So far, there have been 2.3 warnings for every one upside surprise, up from the 1.1 ratio at this time in the second quarter, First Call said, and 2.0 at this time in the first quarter.

"That indicates that we are going to have a tough pre-announcement season," Hill said, referring to the period that grows busier over the next three weeks and ebbs when companies start releasing third-quarter results in mid-October.

Before EDS and J.P. Morgan, McDonald's (MCD: Research, Estimates) said third-quarter profits will fall as much as 9.5 percent below analysts' expectations.

That was after Genzyme General (GENZ: Research, Estimates) said slack sales of its kidney disease drug Renagel would hurt upcoming results. Honeywell International (HON: Research, Estimates) and Lucent Technologies (LU: Research, Estimates) also disappointing investors this month.

The technology and telecom sector is where the bulk of those warnings are coming from, according to First Call, which could not provide specific details. Consumer cyclical companies comprise the fewest shortfalls.

Not all the pre-announcements have been bad. Ford Motor Co. (F: Research, Estimates) said it expects to post a third-quarter profit, surprising Wall Street analysts who expected the No. 2 automaker to lose money. Procter & Gamble (PG: Research, Estimates) raised its sales and earnings estimates for the current quarter earlier this month, joining H&R Block (HRB: Research, Estimates).

Still, overall third-quarter profits are seen rising 8.9 percent from year-ago levels, down from the 16.6 percent advance that analysts surveyed by First call expected on July 1st.

If the gain holds, it will be only the second quarter among the last seven periods when corporate earnings enjoyed year-over-year gains.