Wet weather in the Pacific Northwest
Hourly GOES-18 Hemispheric views, above, from 2140 UTC on 1 December to 2040 UTC on 4 December, (from the CSPP Geosphere site) show the development of a strong system in the Gulf of Alaska. This system is tapping into an airstream rich in moisture that augurs for a wet period along the Pacific Northwest coast. Flood watches and have been issued from western Washington and Oregon. MIMIC Total Precipitable Water fields in December ending at 1500 UTC on 4 December, below, show that some of the moisture in the North Pacific may have been part of the Kona Low that drenched Hawai’i last week.
![](https://cimss.ssec.wisc.edu/satellite-blog/wp-content/uploads/sites/5/2023/12/comp20231201.0000_to_1204.1500anim.gif)
Airmass RGB imagery from GOES-18, below (from this OSPO site), shows the well-developed cyclone with the characteristic orange signal in the airmass RGB denoting air with a large Potential Vorticity signal (as confirmed in this cross-section from1800 UTC on 4 December, take from this site).
![](https://cimss.ssec.wisc.edu/satellite-blog/wp-content/uploads/sites/5/2023/12/G18_sector_np_AirMass_48fr_20231204-1636.gif)
For more information on this event, refer to the websites of the National Weather Service Offices in Seattle, Portand and Medford.