From the NWS Hanford Forecast Discussion, upper air flow is from the south:
Quote
NWS Hanford
AS THE HIGH NUDGES EAST IT HAS OPENED THE DOOR TO MORE MONSOONAL
MOISTURE TO MOVE NORTHWARD INTO THE REGION. WE HAVE HAD A FEW
THUNDERSTORMS DEVELOP THIS AFTERNOON OVER THE HIGHER ELEVATIONS OF
THE SIERRA NEVADA. AN EASTERLY WAVE MOVING ACROSS SOUTHERN ARIZONA
ALONG WITH A SOUTHERLY FLOW IN THE MID LEVELS WILL AID IN
BRINGING THE MOISTURE NORTHWARD LATE TONIGHT AND FRIDAY WHICH WILL
BRING A BETTER CHANCE OF THUNDERSTORMS FOR FRIDAY AFTERNOON.
Severe T-Storm near Susanville, NWS Reno is forecasting possible strong to severe tomorrow.
Edit: Was a Severe T-Storm Warning when I looked at weather.gov earlier, now it's "just" a Special Weather Statement for strong thunderstorms.
Edited 1 time(s). Last edit at 07/25/2013 06:41PM by ttilley.