SAN DIEGO (FOX 5/KUSI) -- Cool and cloudy conditions have held strong for Wednesday and will continue for Thursday as a low pressure system moves over the Western U.S. for the second half of the week. The marine layer was expansive as of noon Wednesday, extending into the inland valleys with limited clearing for beaches and a few miles inland.  Strong onshore flow and deepening marine layer could lead to some patchy drizzle Thursday morning with better chances of some measurable rain (light rain) on tap for Thursday night and Friday morning.  This system isn't favorable when it comes to precipitation, so likely most areas will only pick up a few hundredths an inch of rain while others may not get any.  West winds will increase significantly for mountains and deserts tomorrow afternoon with gusts 40 to 50 miles per hour. Winds will shift generally into a more northerly track for Friday.  Warmer, drier weather will take over for the weekend into early next week.