B737 first officer reported overshooting an altitude restriction on the OAKES2 RNAV arrival into oak...

Narrative:

We were flying to oak and on the arrival; the oakes 2 RNAV; we had to deviate due to some thunderstorms and following deviation were direct bannd. We were in a descent to FL200 when we received a radio switch to another center frequency. We checked in and were given a descent via on the oakes 2 runway 30 transition. We set the bottom altitude because we were on path. We then receive a couple of other transmissions from center modifying the clearance slightly. He said several things; I don't remember exactly; but at the end; it was descend now to FL190 and then descend via when you rejoin the arrival; since we were direct to bannd. I think he said when you rejoin at bannd. We were on the path and had a descend via clearance; so the captain did not change the MCP altitude. ATC was communicating with us to slow to 250 knots. So while we were slowing down; I noticed that we were maybe three miles or less from bannd below FL190; however; we were still on the path. So this was not correct in accordance with the clearance; as we discussed later. After discussing we should have requested 17;000 ft (bottom altitude at bannd) for a descent altitude prior to bannd or set FL190; though less optimal; since it would have put us high on the path. The distraction and some communication confusion led to us not comprehending that the altitude we were given was not on the path and so we could not trust VNAV and should have entered FL190. Center never said anything about the altitude to us and handed us over to norcal approach. After the first clearance; I did not recognize my bias for the descend via. I should also have coordinated with the captain to reset the MCP altitude to FL190 to ensure we did not go below that altitude until beyond bannd. So always reset the altitude. Then clarify with ATC when clearances have ambiguity.

Original NASA ASRS Text

Title: B737 F/O reported overshooting an altitude restriction on the OAKES2 RNAV arrival into OAK. ATC routing off the arrival was cited as contributing.

Narrative: We were flying to OAK and on the arrival; the OAKES 2 RNAV; we had to deviate due to some thunderstorms and following deviation were direct BANND. We were in a descent to FL200 when we received a radio switch to another Center frequency. We checked in and were given a descent via on the OAKES 2 Runway 30 transition. We set the bottom altitude because we were on path. We then receive a couple of other transmissions from Center modifying the clearance slightly. He said several things; I don't remember exactly; but at the end; it was descend now to FL190 and then descend via when you rejoin the arrival; since we were direct to BANND. I think he said when you rejoin at BANND. We were on the path and had a descend via clearance; so the Captain did not change the MCP altitude. ATC was communicating with us to slow to 250 knots. So while we were slowing down; I noticed that we were maybe three miles or less from BANND below FL190; however; we were still on the path. So this was not correct in accordance with the clearance; as we discussed later. After discussing we should have requested 17;000 ft (bottom altitude at BANND) for a descent altitude prior to BANND or set FL190; though less optimal; since it would have put us high on the path. The distraction and some communication confusion led to us not comprehending that the altitude we were given was not on the path and so we could not trust VNAV and should have entered FL190. Center never said anything about the altitude to us and handed us over to NorCal Approach. After the first clearance; I did not recognize my bias for the descend via. I should also have coordinated with the Captain to reset the MCP altitude to FL190 to ensure we did not go below that altitude until beyond BANND. So always reset the altitude. Then clarify with ATC when clearances have ambiguity.

Data retrieved from NASA's ASRS site 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.

Attributes
ACN	1543495
Time
Date	201805
Local Time Of Day	0601-1200
Place
Locale Reference	ZOA.ARTCC
State Reference	CA
Environment
Light	Daylight
Aircraft 1
Make Model Name	B737 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	Descent
Flight Plan	IFR
Person 1
Function	First Officer Pilot Not Flying
Experience	Flight Crew Last 90 Days 230 Flight Crew Type 230
Events
Anomaly	ATC Issue All Types Deviation - Altitude Crossing Restriction Not Met Deviation - Altitude Overshoot Deviation - Procedural Clearance Deviation - Procedural Published Material / Policy Inflight Event / Encounter Weather / Turbulence

B737 first officer reported overshooting an altitude restriction on the OAKES2 RNAV arrival into oak. ATC routing off the arrival was cited as contributing.