Well, it’s February and it’s the East Pacific off of California, so the short answer is no. But. . .what an amazing structure, right? We haven’t seen anything this good looking in the tropical Atlantic in years! But I digress. . .
The first image was collected four hours before the second image and you can see how the center of the intense storm developed an “eye-like” feature (images courtesy of NASA SPoRT). Notice the distribution of the pinks and reds in both images as well. That is dry, stratospheric air filling the center of the strong upper-level low (~300-500 mb). The second area shows an additional area of pink approaching the southern California coast. This area is associated with strong instability that has led to rare California thunderstorms.
So, how do we know if there is stratospheric air?
The first image above is the AIRS Total Column Ozone product developed at NASA SPoRT. The color bar on the left is not correct. The main idea is that the warmer (cooler) the colors, the more (less) ozone is in the atmospheric column. The green colors indicate ozone levels above 200 Dobson Units (ozone unit of measurement) with the magenta areas indicating ~500 Dobson Units. The second image shows the AIRS Ozone Anomaly product with the first level of blue indicating 125% of normal, while the yellow region indicates >200% of normal ozone at that latitude and geographic location. Stratospheric air is associated with high levels of ozone and potential vorticity which can help identify the strength of the upper-level low. These images show the connection of this ozone pocket with the “reservoir” of ozone located in the northern latitudes at this time of year.
As the upper-low cut off and became stacked over the surface low (~971 mb), you can see how the high concentration of ozone becomes more focused over the storm. Once again, the magenta coloring indicates ozone levels >500 Dobson Units. The anomalies are more incredible with a large area of >200% of normal directly west of southern California.
I will continue to work with forecasters at OPC, TAFB, SAB, and WPC on discovering ways to use these products in conjunction with the RGB Air Mass products to gauge storm strength and look for signals upstream of developing tropopause folds and stratospheric intrusions.
The ozone isn’t the only impressive part of this storm. Notice the occasional bursts of lightning within the spiral bands of the parent storm. Although not completely unusual, this is a great indicator of how much energy is available to this storm.
I put together a longer animation of the GOES-Sounder RGB Air Mass product with the GLD-360 lightning strikes overlaid. Note the first system that came ashore in California earlier this week, then moved over the four-corners regions with plenty of lightning, especially for this time of year. The current storm is seen lurking offshore with more lightning developing in a band of thunderstorms that moved from Los Angeles to just north of San Diego. This system will be responsible for the next bought of winter weather for the Midwest to the Mid-Atlantic next week.
Thanks for reading and as always, feel free to contact me with questions and feedback!
Great post Michael. Nice example of using the RGB and Ozone products together. Lucky you had some timely MODIS passes during the best intensification of the low too!
Definitely a lucky find and great passes. During training yesterday, a question was asked on how to use the ozone product to forecast as this example shows the system already formed. I think this can be analyzed more in the coming weeks.
Love this case and really enjoyed your write up. Some excellent examples of the RGB Air Mass product as well as the AIRS products. Well done Michael!
Just now reading this blog, awesome analysis Michael!