| There was a discussion at another message board about whether Barry was a hurricane or not. Some people weren't using the right recon data and in case anything on my site was unclear, I wanted to explain it to people. I thought it might be helpful to post it here too if anyone uses the recon system at my site or HurricaneCity. The NHC already explained why it was hurricane in their 10am CDT discussion: "Between 11-12Z, the National Ocean Service station at Eugene Island, Louisiana, reported sustained winds of 62 kt and a peak gust of 74 kt at an elevation of about 10 m. Doppler radar winds from the Slidell WSR-88D suggested surface winds of 60-65 kt as well. In addition, an Air Force Reserve Hurricane Hunter aircraft reported SFMR wind estimates of 60-63 kt near Eugene Island, and 850-mb flight-level winds of 72 kt. Based on these data and the possibility that the strongest winds were not sampled, it is estimated that Barry became a hurricane around 11-12Z despite its less than classical appearance in satellite imagery. It should be noted that hurricane-force winds are limited to a small area east of the center, and that the upgrade to a hurricane means little in terms of the overall impacts from Barry." From archive of 10am CDT Saturday discussion: https://www.nhc.noaa.gov/archive/2019/al02/al022019.discus.013.shtml? Additionally, recon data from right around the time the discussion would have been posted further indicated it was a hurricane. The discussion was certainly already written, if not posted, when that recon took place (around 9:45am and 9:48am CDT), so that was not mentioned in the 10am CDT discussion and by 4pm CDT they weren't talking about the recon that morning. What I posted at another site... The NHC has already provided the basis for why they upgraded, but I did want to speak about the recon part of it. Below are from the last mission, Air Force mission 11. Ob 23: http://tropicalatlantic.com/recon/recon.cgi?basin=al&year=2019&product=hdob&storm=Barry&mission=11&agency=AF&ob=07-13-143600-23-1006.4-75-56 14:45:30Z: 28.983N 91.133W Flight Level Wind (30 sec. Avg.): 75 knots (86.3 mph) Ob 24: http://tropicalatlantic.com/recon/recon.cgi?basin=al&year=2019&product=hdob&storm=Barry&mission=11&agency=AF&ob=07-13-144600-24-1002.5-74-63 14:48:00Z: 29.100N 91.250W (about 9 miles offshore) Flight Level Wind (30 sec. Avg.): 74 knots (85.2 mph) Peak (10 sec. Avg.) Flight Level Wind: 76 knots (87.5 mph) SFMR Peak (10s Avg.) Sfc. Wind: 64 knots (73.6 mph) ... Noted as suspect 14:48:30Z: 29.117N 91.283W (about 8.5 miles offshore) Flight Level Wind (30 sec. Avg.): 71 knots (81.7 mph) Peak (10 sec. Avg.) Flight Level Wind: 73 knots (84.0 mph) SFMR Peak (10s Avg.) Sfc. Wind: 63 knots (72.5 mph) Both obs around 840mb, 5,000 feet. In ob 24 noted the SFMR was 64 knots, but noted as suspect, and in the next 30 seconds the SFMR was 63 knots and not noted as suspect. The 30 second flight level wind during the 30 seconds the SFMR was noted as suspect was 74 knots. 10 second flight level wind was 76 knots. The highest SFMR was about where the highest flight level winds were. It was offshore. While the waters may be shallow out there, I don't know, the estimated surface winds seem like they are likely valid even if many are noted as suspect at that time. Given the flight level winds, they seem perfectly reasonable. Some notes about my site, Tropical Atlantic, in case some of the numbers seem confusing. Here is a list of missions for Barry that had HDOB messages: http://tropicalatlantic.com/recon/recon.cgi?basin=al&year=2019&storm=Barry&product=hdob Suspect values are not included in the winds. So the "Highest SFMR Peak (10s Avg.) Sfc. Wind" is 63 knots for mission 11 in that list. In mission 8 there was a 65 knot estimate that was not noted as suspect. That did not seem to be representative, though it may not have been completely invalid. When there is a question, I usually leave the value in that list. If something is very inaccurate I remove the high, or low (such as pressure), reading from the column by removing the value from the file name for the ob on my site. That is where values for the list come from. If I change the file name (the "ob" part of the links above), which was created based on values in the ob, the list will be updated. 10 second flight level winds are not included in the list. While the 63 knots should perhaps be 64 knots, I never make a change like that. If something is noted as suspect I would never modify it unless the NHC specifically said it should be in a discussion. This is a list of missions with vortex messages with Barry: http://tropicalatlantic.com/recon/recon.cgi?basin=al&year=2019&storm=Barry&product=vortex Only vortex messages processed get included in the high and low values in that list. The last mission only had one vortex message. Any higher wind readings after the vortex message was completed were therefore not included in the vortex message. Because suspect readings are usually not in a vortex message, suspect readings are unlikely to be included in the list. For mission 11, the one vortex message had 72 knots for highest flight level wind and 63 knots for surface wind. There were higher winds found later and they were not included in the vortex message. The 72 knots was from Ob 04. (peak 10 second flight level wind) The 63 knots (10 second estimated surface wind at 29.383N 91.400W) was from Ob 05. It was actually extremely close to land, if not over it, and was likely not accurate because at the very least it would have been very shallow. But it was included in the vortex message. Mission 8 had a vortex message with a 73 knot flight level wind. Because vortex messages have likely undergone more review, the values for the main storm list here: http://tropicalatlantic.com/recon/recon.cgi?basin=al&archive=2019 Use vortex messages. That means these are the high values for Barry noted on my site: Highest Flight Level Wind: 73 knots Highest Est. Surface Wind: 63 knots That 73 knots comes from mission 8. But mission 11 actually had 76 knot 10 second flight level winds in Obs 24 and 30. And that 63 knots is actually a reading that should likely have been suspect, but there just happened to be another 63 knots after the vortex messages were no longer released that would have also made the value 63 knots. Because 64 knots was suspect, it would not have likely been included in the vortex message had one been released at that point. The point is, values on my site need to be researched more closely if people are getting them from it. The archive is raw because it operates in real time. I rarely make any changes to a file name so that a list doesn't reflect a value that clearly seems wrong. The ob of course still remains. And for the storm summary that uses vortex data, I don't see a better way. Other data would be even less reviewed and more subject to error. I have noted on pages how data is calculated in those lists and if I were to force a modification to a particular set of data it would be very confusing. So the numbers in the archive will always be: Highest Flight Level Wind: 73 knots Highest Est. Surface Wind: 63 knots For Barry. |