Saturday, November 8, 2014

Scatterometer Sensing of Nuri

Radar scatterometers send out a pulse of microwave energy that is scattered by wind-driven waves on the ocean.  The amount and characteristics of the energy scattered back to the receiver allows us to infer the speed and direction of the surface flow.  There are several scatterometers on polar-orbiting satellites today and you can look at the latest overpasses here.

Below is a composite of scatterometer overpasses of Nuri at around 0000 UTC 8 November when it was sitting near the Commander Islands east of the Kamchatka Peninsula.  You can see two main areas of intense low level flow, one just north of the occluded front, which extends eastward from the low center, the other to the south of the low.  Strong winds in the latter region are sometimes referred to as a "sting jet" or the "posionous tail of the bent-back occlusion."  Yes, meteorologists do have imaginations.

Source: NESDIS
The color scale unfortunately maxes out at 50 knots and there's enough overlap of the wind barbs to make it difficult to determine the maximum winds. I suspect they are in the 60–70 knot range.


  1. I'm enjoying these posts covering Nuri. I've heard some of the major media outlets talking about how it will eventually affect the jet-stream and bring artic air to the east. Will we see any difference in weather here because of Nuri in the end?

    1. The extratropical transition of Nuri sets off a sequence of events that ultimately leads to the development of a pronounced high-latitude blocking ridge over northwest Canada and Alaska. This contributes to a surge of cold air that will push into the western U.S. late Sunday and Monday and drop our temperatures on Monday. Later next week, we may be affected by a system that cuts under the ridge, but we'll have to see if that comes together.