It is blowin up there

Check out these winds aloft forecast for SFO area!

********  FD Winds Aloft Forecast  ********

DATA BASED ON 301200Z                                                REQUESTED
VALID 010000Z   FOR USE 2100-0600Z. TEMPS NEG ABV 24000              ALTITUDE
FT  3000    6000    9000   12000   18000   24000  30000  34000  39000  5500
SFO 0240 0258+07 0169+07 0170-01 3572-15 3476-27 338945 339153 327957 0255+08

And how about these pireps from the area?

LVK UA /OV LVK-LVK090004 /TM 1834 /FL040 /TP PA44 /TB MOD 040/BLO
SJC UA /OV NUQ135007 /TM 1826 /FL045 /TP BE35 /WV 36050KT /TB NEG /RM WIND FROM THE NORTH 50KTS  030-060

The prog charts shows the steep pressure gradient between the High Pressure and the low pressure... and then the associated impacts to flying are noted in the airmets below... Also a sigmet issued for the Sierras




check out the close isobars



Airmet T - Turbulence

Airnet T