Narrative:

On a routine scheduled flight sfo-mry the WX was reporting thunderstorms in all quadrants. (Imbedded) thunderstorms. We flew in 1/2 hour earlier and were able to get vectors around the WX we did not want to fly near. But on departure this time bay departure was very busy with traffic and unable to give us our requested altitude and route of flight to avoid WX (thunderstorms). We then proceeded on our assigned route and altitude of flight. Approximately 8 mi southeast of osi we ran into an imbedded thunderstorm just developing and not showing up on our onboard WX radar. The up and down drafts in the cell were moderate to almost severe. We were unable to maintain our assigned altitude of 7000 ft. The deviation was a few hundred ft below and above our assigned altitude. There was no conflict or 'traffic.' we reported our problem and had to wait a few (long mins) before we were allowed to deviate. The controller was very professional but said due to 'traffic' unable. Also he said they have no ground based WX radar to help them in keeping aircraft away from thunderstorms. This thunderstorm at the time was not painting on our screen but I am sure it did paint in short time. I know money is always an issue but if tv stations (local) have radar or are able to use it why can't controllers on the west coast have it also. It can't hurt.

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Original NASA ASRS Text

Title: ACR FLC WOULD LIKE MORE RADAR WX INFO FROM THE GND. WOULD LIKE ARTCC CTLRS TO BE ABLE TO LOCATE TSTMS ACCURATELY.

Narrative: ON A ROUTINE SCHEDULED FLT SFO-MRY THE WX WAS RPTING TSTMS IN ALL QUADRANTS. (IMBEDDED) TSTMS. WE FLEW IN 1/2 HR EARLIER AND WERE ABLE TO GET VECTORS AROUND THE WX WE DID NOT WANT TO FLY NEAR. BUT ON DEP THIS TIME BAY DEP WAS VERY BUSY WITH TFC AND UNABLE TO GIVE US OUR REQUESTED ALT AND RTE OF FLT TO AVOID WX (TSTMS). WE THEN PROCEEDED ON OUR ASSIGNED RTE AND ALT OF FLT. APPROX 8 MI SE OF OSI WE RAN INTO AN IMBEDDED TSTM JUST DEVELOPING AND NOT SHOWING UP ON OUR ONBOARD WX RADAR. THE UP AND DOWN DRAFTS IN THE CELL WERE MODERATE TO ALMOST SEVERE. WE WERE UNABLE TO MAINTAIN OUR ASSIGNED ALT OF 7000 FT. THE DEV WAS A FEW HUNDRED FT BELOW AND ABOVE OUR ASSIGNED ALT. THERE WAS NO CONFLICT OR 'TFC.' WE RPTED OUR PROB AND HAD TO WAIT A FEW (LONG MINS) BEFORE WE WERE ALLOWED TO DEVIATE. THE CTLR WAS VERY PROFESSIONAL BUT SAID DUE TO 'TFC' UNABLE. ALSO HE SAID THEY HAVE NO GND BASED WX RADAR TO HELP THEM IN KEEPING ACFT AWAY FROM TSTMS. THIS TSTM AT THE TIME WAS NOT PAINTING ON OUR SCREEN BUT I AM SURE IT DID PAINT IN SHORT TIME. I KNOW MONEY IS ALWAYS AN ISSUE BUT IF TV STATIONS (LCL) HAVE RADAR OR ARE ABLE TO USE IT WHY CAN'T CTLRS ON THE W COAST HAVE IT ALSO. IT CAN'T HURT.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.