The first hint that the global economy’s recent weakness is creeping into the US arrived in today’s preliminary November update of the Markit US Manufacturing Purchasing Managers Index (PMI). This survey of business conditions in the manufacturing sector reflected slower growth for this month’s flash estimate. Dipping to 54.7, the PMI’s slide — the third monthly decline in a row — shows that manufacturing activity in the US increased this month at the slowest pace since January.

Despite the recent declines, today’s PMI data continues to show that the cyclically sensitive manufacturing sector is still expanding, and at a rate that’s well above the neutral 50.0 mark that separates growth from contraction. But with signs of stagnation in Europe, recession in Japan, and a slowdown in China’s growth, the potential for deceleration in the US economic trend is plausible and perhaps inevitable.

“Export market weakness holds the key to the recent slowdown [in the US Manufacturing PMI], with manufacturers reporting the largest drop in export orders for nearly one and a half years,” says Markit’s chief economist, Chris Williamson, in a press release with today’s update. He adds, however, that the payrolls data for manufacturing still looks encouraging… for now.

There’s some reassurance from manufacturers continuing to boost their payroll numbers at a robust pace, but with backlogs of work showing almost no growth, the rate of job creation looks likely to moderate in coming months unless new order inflows pick up again.

The bottom line: today’s report suggests that US growth overall will lose some of its recent momentum. As a result, November may be the turning point that marks the beginning of a period of deceleration. It’s still early for deciding what’s in store for this month’s US macro profile, but for the moment the initial data is starting off on a softer note relative to October’s robust trend.

We’ll have a better sense of how the US economy is faring in November after seeing Monday’s PMI report for services, followed by the competing ISM Manufacturing Index, which is scheduled for a November update early next month (Dec. 1). Meantime, it’s reasonable to manage expectations down a notch. The US is still poised to deliver modest growth in the near term, but today’s PMI report serves as a reminder that we’re in a globalized economy, and at the moment that’s not particularly helpful for the US.