Re: CIMSS / SSEC Weather Briefing 10/23/2015 Patricia
Posted by Chris in Tampa on 10/27/2015, 10:53 pm
Very interesting.

They actually mentioned something I was looking into, mesovortices.

The other thing they mentioned is that the dropsonde system on the NASA WB-57 is still experimental. I would love to get that data eventually, like I do with the Global Hawk.

If that 185mph sustained wind was accurate, I think the only way it could be would be due to something like a microburst or mesovortices.

From the damage in places like Emiliano Zapata and Costa Careyes ( Before: http://www.careyes.com/ After: http://finance.yahoo.com/video/super-rich-count-cost-mexico-035810945.html ), the damage appears as though it was not as bad as expected. (Some buildings were still leveled in some areas in the region, but most of those did not appear to be built well.) There are a lot of moderate to good constructed buildings still standing.

In the image below you can see where Costa Careyes is located in comparison to the station, up 295 feet, that recorded the high wind. And the video at the link above shows the damage at the resort area, which is between where the eye and the high wind recorded at that station.



That wind might not be valid given the damage seen at Costa Careyes, but it could still be something like a mesovortices. Based on aircraft data, damage and location of that station being on the 'weaker' side of the storm, if valid it wouldn't seem to be representative of the winds in the rest of the eyewall. (Accounting for elevation as well.) However, it brings up an interesting question. If it was valid or even used as a hypothetical example, what should the wind be for the storm? If a tornado occurs in a wind band, you don't use the wind speed as the sustained wind for the storm. But what about the eyewall? Are mesovortices something that would even make it to the surface? Or even a microburst, would you use that as the sustained wind speed because it happened to occur in the eyewall? Or would you not use it? So many other storms, if something like this were possible but not often, or ever, observed, would have lower wind speeds because you didn't happen to capture the small scale feature. It's been something I have been thinking about.



A little about mesovortices:
http://www.met.nps.edu/~mtmontgo/papers/hurricane_mesovortices.pdf
http://andrew.rsmas.miami.edu/papers/KMS2002_MWR.pdf




"The peak tangential velocity is found to occur in the mesovortices and is roughly
50% greater than the parent vortex that supports them. The measurements provide
insight into recent observations of excessive wind damage in landfalling storms and
support the hypothesis that intense storms contain coherent vortex structures in the
eyewall region with higher horizontal wind speeds locally than the parent hurricane."

"Eyewall mesovortices possess horizontal scales smaller than the diameter of the eye
yet are of similar size or larger than the individual cumulus clouds that constitute the
eyewall. While intriguing scientifically, they are also of significant practical concern.
Originating in the quasi-circular shear layer just inside the eyewall and believed to
form via Kelvin-Helmholtz (barotropic) instability of this curvilinear shear layer,
eyewall mesovortices pose a threat to the safe operation of reconnaissance aircraft
(Marks & Black 1990; Black & Marks 1991). Mesovortices concentrate the angular
momentum of the parent vortex into a relatively small area and can produce
swaths of heightened destruction for intense landfalling hurricanes when juxtaposed
with convective downdraughts or boundary layer rolls (Wakimoto & Black 1994;
Willoughby & Black 1996). Eyewall mesovortices are analogous to the 'suction vortices'
of tornadoes (Fujita 1971; Rotunno 1984; Finley 1997; Fiedler 1998)."

"Our findings support the hypothesis that intense hurricanes contain coherent vortex
structures with significantly stronger near-surface winds locally than the parent vortex.
If the findings are found to be consistent with future in-situ observations, it would
indicate the need to recognize the potential hazard of intense mesovortices in construction
codes and emergency management planning for coastal regions threatened
by intense landfalling storms."


From PowerPoint file here: https://noaahrd.wordpress.com/2015/05/19/2015-hurricane-field-programintensity-forecast-experiment-hfpifex-planning-meeting/



In the last recon mission there were some sondes that were never released.



Winds are momentary gusts.

Sonde: Labeled as A

Sonde did not make it to the surface:

813mb  100° (from the E) 160 knots (184 mph)
792mb  120° (from the ESE) 191 knots (220 mph)
762mb  135° (from the SE) 167 knots (192 mph)
700mb  210° (from the SSW) 186 knots (214 mph)
699mb  210° (from the SSW) 187 knots (215 mph)

Sonde: Labeled as B

927mb (Surface)  150° (from the SSE)  115 knots (132 mph)
920mb  160° (from the SSE)  112 knots (129 mph)
911mb  170° (from the S)  120 knots (138 mph)
901mb  175° (from the S)  120 knots (138 mph)
883mb  185° (from the S)  132 knots (152 mph)
873mb  190° (from the S)  126 knots (145 mph)
865mb  190° (from the S)  133 knots (153 mph)
859mb  190° (from the S)  129 knots (148 mph)
850mb  190° (from the S) 134 knots (154 mph)
770mb  205° (from the SSW)  117 knots (135 mph)
699mb  215° (from the SW)  131 knots (151 mph)

Surface and Standard Isobaric Surfaces:

927mb (27.38 inHg)  Surface (Sea Level)   150° (from the SSE)  115 knots (132 mph)
925mb 24m (79 ft)  150° (from the SSE) 115 knots (132 mph)
850mb 776m (2,546 ft)  190° (from the S) 134 knots (154 mph)
700mb 2,475m (8,120 ft)  215° (from the SW) 131 knots (151 mph)

Google Earth map with unreleased sondes:
http://tropicalatlantic.com/temp/2015/10-27/map_with_unreleased_sondes.kmz
It is important to note that some of the data is wrong. The first sonde I labeled as A did not make it to the surface. It lists a surface pressure as if it did. There is a program, Aspen, where I could have updated that message correctly easily, but I wanted to include it as is. I don't have that data on the rest of my site because I found it on NOAA's server where I get radar data and I didn't want to use unreleased data in my system.

I was looking to see if there was any evidence of mesovortices based on radar and satellite data.

Visible satellite data from GOES East and West, side by side, in this CIMSS blog post:
http://cimss.ssec.wisc.edu/goes/blog/archives/19838

And radar data I created from Google Earth for the last mission:



It was hard to tell. The radar data I have is not high enough in quality to determine I don't think. I can't see anything definitive that shows any mesovorticies from that or satellite data.

They do have some interesting radar products from the tail doppler radar for the Oct. 23rd mission: http://www.aoml.noaa.gov/hrd/Storm_pages/patricia2015/radar.html
Vertical profiles, where the horizontal white line across indicates the path of the plane.

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CIMSS / SSEC Weather Briefing 10/23/2015 Patricia - cypresstx, 10/26/2015, 9:28 am
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