- Date
- Issued at
- 11:00 PDT/PST
- Created by
- Rossby Wave
The "Glass Half Empty" Trough
More widespread shower and thunderstorm activity will occur today and Monday as a negatively-tilted upper trough sets up in the Gulf of Alaska. The province will remain wet and unsettled under this negatively, aka "Glass Half Empty", trough until Tuesday when a ridge begins to build and steers the wet weather solely to the north coast and Alaskan Panhandle with a possible warm spell starting Thursday onwards.
The 500 mb animation depicted above shows an upper low moving over the Gulf of Alaska. This will help to set up a negatively-tilted upper trough which will be the main driver of weather for the next two or three days. Rain will begin over the BC coastline this morning and this afternoon followed by the interior later in the afternoon and in the evening.
The negatively-tilted upper trough remains until a ridge peaks through Tuesday bringing fair weather. However, this will steer a frontal band of precipitation to the north coast on Wednesday.