Question

what were the
air masses around Salem, Oregon from May 6th to 7th.

Answer 1

I don’t have enough information to give a definite answer — which year do you mean (e.g., May 6–7, 2025)? Do you mean the surface air mass over Salem (Willamette Valley) or the origin of the air (trajectory/parcel source) and for what times (UTC/local)?

What I can do once you tell me the year and whether you want surface or upper-air detail:
- look at archived surface analyses and NWS forecast discussions to identify fronts and the surface air mass type (e.g., maritime polar, maritime tropical, continental polar, continental tropical),
- examine nearby radiosonde soundings (Portland/KPDX) or reanalysis (ERA5/NCEP) at 850 hPa to classify air-mass thermodynamic character,
- (optionally) run backward trajectories (NOAA HYSPLIT) from Salem coordinates to show the air-parcel origin.

If you just want a quick, general description for early May in the Salem area: the region is most often under maritime polar (mP) influence from the north Pacific (cool, moist) or occasionally maritime tropical (mT) when a southerly flow brings warmer, moister subtropical Pacific air. Continental polar (cP) intrusions from the interior are less common but possible with strong cold fronts.

Tell me the year (and whether you want surface vs. trajectory/upper-air analysis) and I’ll proceed.