Influence on Terrain and Weather Records
As the storm came across land, water vapor was pushed up over the terrain where it cooled, condensed, and fell mainly as rain. The majority of the storms rainfall fell between the Pacific coast and the crest of the Cascade Mountains. Some mountainous locations in Washington state were anticipated to get 5– 9 inches (130– 230 millimeters) of water in a 36-hour period ending on the afternoon of December 5.
In the lowlands, Seattle set a day-to-day rains record for December 4 of 1.51 inches (38.3 millimeters), according to news reports. Much heavier rains moved toward northwest Oregon on December 5, with 2– 6 inches forecast to fall in the Coast Range that day. Flood watches were issued as rivers swelled.
Record-Breaking Temperatures and Water Supply Relief
Both Portland and Seattle registered brand-new high temperature level records during the storm. Portland topped out at 65 degrees Fahrenheit (18 degrees Celsius) on December 4, setting a record for that date and connecting the December all-time high temperature record.
The rain must help eliminate pressure on regional water products. In the Seattle location, an abnormally dry summer stimulated issues about adequate water for community supplies in addition to fish habitat. Climatic rivers take place frequently in winter season and can account for approximately 50 percent of all rain and snow that falls in the western United States.
NASA Earth Observatory image by Lauren Dauphin, using GEOS-5 data from the Global Modeling and Assimilation Office at NASA GSFC.
Map of the total precipitable water vapor in the atmosphere at 1:30 p.m. Pacific Time on December 4, 2023.
A warm, moisture-laden weather condition system soaked western Washington and Oregon.
An effective atmospheric river streamed towards the U.S. Pacific Northwest in early December 2023. The long current of water vapor delivered warm, wet weather condition to much of western Washington and Oregon, falling daily rains and temperature records and escalating flood and debris flow risks.
Keeping An Eye On Atmospheric Conditions
This map shows the total precipitable water vapor in the environment at 1:30 p.m. Pacific Time on December 4. If all of the water vapor were condensed into liquid, precipitable water vapor is the quantity of water in a column of the environment. The dark green areas on the map highlight the band of wet air flowing northeast from the tropical Pacific. The image was stemmed from NASAs GEOS ADAS (Goddard Earth Observing System, Atmospheric Data Assimilation System), which utilizes satellite data and designs of physical procedures to calculate what is occurring in the environment.
Precipitable water vapor is the amount of water in a column of the atmosphere if all of the water vapor were condensed into liquid. As the storm encountered land, water vapor was pressed upward over the terrain where it cooled, condensed, and fell mainly as rain. Some mountainous locations in Washington state were expected to get 5– 9 inches (130– 230 millimeters) of water in a 36-hour period ending on the afternoon of December 5.
In the Seattle area, an unusually dry summertime stimulated concerns about adequate water for community materials as well as fish habitat.