The fact that yesterday was a leap day would seem to make it stand out, but nature had a say in just how much this day would stand out. From devastating tornadoes in the Midwest to a rapidly intensifying North Atlantic storm that eventually became hurricane force to a strong storm in the Eastern Mediterranean that caused many problems in Turkey, Lebanon, Israel, and Egypt. One of the perks to being a GOES-R “Satellite Champion” at a National Center is that I get to observe many different features on multiple satellite products. I thought these three storms were significant enough to write a blog post on and show just how the new GOES-R era and even current satellite products could be used to enhance our understanding of extratropical cyclones.
Midwest High Impact Storm
This GOES-Sounder RGB Airmass image shows the dry, stratospheric air (pink/orange shading in yellow circle) that is advecting towards the Potential Vorticity anomaly over WI/IA/MN area. There is an intersection between this stratospheric intrusion and the low to mid-level dry air associated with the dry conveyor belt that originates in the desert Southwest. This is where some higher wind gusts were reported around 21z yesterday.
This zoomed in image highlights the Mid-Mississippi Valley where some of the higher non-thunderstorm wind gusts were recorded. Note the pink shading rotating around the upper-low and co-located with the 30-35 knot wind barbs over the area. Wind gusts were in the 50-60 mph range through MO and IL with Lambert-St. Louis International reporting a wind gust to 58 mph and St. Charles, MO reporting at gust to 64 mph. Most likely, the stratospheric intrusion and ample sunshine allowed excellent mixing and thus, excellent momentum transport over the area at this time.
The above image shows a 1923z MODIS RGB Airmass product with the yellow circle highlighting the stratospheric intrusion. Note the two red streaks that feed into the highlighted area, one from the northwest and another from the southwest. I am not sure if the southern one is truly stratospheric in origin, but the northern stream is most likely associated with stratospheric air and PV “roping” as higher PV values rotate around the parent low.
North Atlantic Hurricane-Force Storm
The above images show the strong North Atlantic storm that was producing hurricane force winds last evening. Note the very evident stratospheric intrusion (dark pink) advecting towards the PV anomaly center. The first image shows the storm with a central pressure of 976 mb at 19z. The second image shows the storm at 2345z (963 mb) with an OSCAT high resolution wind pass overlaid to show the surface wind direction and strength. The red flags in the southwest quadrant indicate winds over 65 knots and they are co-located with this stratospheric intrusion, further supporting the notion that downward momentum transport is helping to produce this strong wind near the bent-back front in the comma-head region.
Strong Eastern Mediterranean Storm
These images show the strong Eastern Mediterranean storm that affected Greece, Turkey, Lebanon, Israel, and Egypt with some very adverse weather. The first image shows the six separate advection jets rotating in towards the strengthening PV anomaly near southern Turkey. This is the most extreme case of stratospheric intrusion I have seen as most cases reveal one to maybe three separate streams. I am unsure of what is going on here to create this phenomena, but it is worth investigating further. The second image gives you some indication of wind speeds in the southeastern Mediterranean with ASCAT finding winds between 30 and 40 knots.
This final image is the SEVIRI RGB Dust product which highlights the blowing dust occurring from northeast Egypt and Sinai, to parts of Jordan, Syria, and Iraq. Also notice the dust streams over Saudi Arabia.