Weather Archive for Labor Day Weekend
From Saturday 9/4/04 through Monday 9/6/04

One of the more exciting Labor Day Weekends for local flying in my short term memory.  Pilots successfully crossed Casitas Pass all three days from east to west.

A trough came through on Friday to drop the pressure and the temperatures below 10K.  The Catalina Eddy spun up with wind from the SE on the south coast slopes.

On Saturday, the trough moved off to the east and higher pressure moved overhead.  Somewhat of a transition day, the 6K temp was higher than Friday, but still well below the seasonal norm.  There was enough subsidence to result in a mild Santa Anna type outflow off the desert in the morning hours, but the good lapse rated sucked in the ocean air in the afternoon and the sea breeze front moved up the Santa Clara River.

Sunday's temps peaked higher than forecast.  The air at altitude was in the low end of  the seasonal norm, but the surface temps were well above.  Despite the strong lapse rate on the south coast, the gradients remained offshore which resulted in very little filling flow from the ocean to cool the lower air mass.  The wind at altitude was mostly from the east till mid afternoon.  There was strong local draw in places and SSE wind on the ridge most of the day.  There was also NE/SE convergence over the front range earlier in the day with pilots at Chiefs Peak reporting 10K.

Monday was forecast to be even better, but a look a the middle graph (lapse rate vs. altitude) from the afternoon VGB balloon tells the story.  It was better higher, so once you got low you were stuck.  Might have been better at Pine on Monday.  Surface temps didn't reach the forecasted highs.  Despite reports of building west wind westbound, no one went to the Bluffs.  Chad did point that way from Chiefs, but reported east wind at altitude.  Perhaps a different route?

SD