The job market looks rock-solid, but there are 4 signs it's weakening as labor trends mirror past recessions

• The job market has impressed recently, but there are worrying signals beneath the surface.
• Wall Street forecasters have pointed to four signs of weakness flashing in the US labor market. 
• That weakness heightens recession odds, especially if unemployment begins to rise meaningfully. 

Today's job market looks to be on solid footing, but there are subtle signs that hiring is starting to weaken, upping the odds that a recession strikes. 

The economy added a blowout 303,000 jobs last month, and the unemployment rate remained near historic lows at 3.9%.