Monday, September 28, 2009
The front made it in late this afternoon and early evening as shown by the infrared satellite photo above. Winds really increased this afternoon as the front approached as winds reached 20-25 mph in places. If you look carefully, you will see the mottled cloud pattern over the ocean...those are the classic postfrontal instability showers produced by cooler air aloft over warmer water. You will notice an area of enhanced showers out there...that is associated with an upper level trough (see map for 500 mb, the lines give the height of this pressure above sea level). So expect showers and sunbreaks tomorrow.
The latest radar image shows the frontal precipitation on the east side of the sound and an area of enhanced showers from Sequim to Whidbey Island...this is from a convergence zone to lee of the Olympics...since winds are now from the SW aloft. All convergence zones are not over Puget Sound! It all depends on the wind direction.
Posted by Cliff Mass at 10:18 PM