Skip to content

Patricia’s Wind Speeds At Landfall

October 25, 2015

By Paul Homewood 

 

image

http://blog.metoffice.gov.uk/2015/10/24/the-latest-on-hurricane-patricia/

 

As we know, Hurricane Patricia caused far less havoc in Mexico than had been predicted just a few hours before. In part, this was due to the fact that the strongest part of the storm made landfall at Cuixmala, a sparsely populated area, which lies midway between Puerto Vallarta and Manzanillo, each about 50 miles distant.

 

image

 

 

According to the official reports, satellites recorded 1-minute sustained speeds of 165 mph at landfall. This alone must cast a certain amount of doubt over claims of 200 mph winds shortly before landfall.

However, there were also rumours of higher wind speeds:

 

ScreenHunter_2927 Oct. 25 10.22

https://twitter.com/hashtag/Patricia?src=hash&ref_src=twsrc^tfw

 

But now things get a bit murky.

 

The Mexican Met Agency have an online facility for checking weather data at hundreds of stations around the country. There is an automatic station at Cuixmala, and the nearest coastal one is Manzanillo.

 

ScreenHunter_2931 Oct. 25 13.04

http://smn.cna.gob.mx/emas/

 

When we check the sustained wind speeds at Cuixmala, we find that they peak at 231 kmh, or 144 mph. As these are only hourly figures, they will likely underestimate peak speeds. (Indeed on the 10-minute option they offer, speeds reached around 240 mph – annoyingly I did not save this at the time, and naturally it has now been replaced by more recent data on the system.)

 

JA22vel1_60m

 

However, we have a big problem with the readings at Cuixmala. Below is the chart for wind gusts (rafaga). Apparently they reached 1800 kmh!

 

JA22vel2_60m

 

The records at Cuixmala are therefore totally worthless, leaving us only with a theoretical satellite figure of 165 mph.

There is a huge problem with this, and that is that satellites can measure wind speeds at every part of the storm. We have seen just how sparse land based measuring stations are, so it is extremely unlikely that such stations would have picked up the highest speeds in pre-satellite era storms.

If we take the Great Hurricane of 1959, mentioned yesterday, sustained wind speeds of “at least” 156 mph, and probably around 160 mph, were recorded in Manzanillo.

It is highly improbable that the highest windspeeds occurred precisely in Manzanillo, and therefore follows that the 1959 hurricane at least matched the 165 mph of Patricia.  

12 Comments
  1. A C Osborn permalink
    October 25, 2015 3:06 pm

    Paul, so why isn’t the damage the same?
    There are very few trees down.

    • October 25, 2015 3:53 pm

      There is some evidence of trees down and corregated roofs blown off at Cuixmala.

      http://uk.reuters.com/article/2015/10/25/uk-mexico-storm-patricia-idUKKCN0SI00820151025

      However compare with the 1959 storm

      In Colima, all coconut plantations were blown down and thousands of people were left out of work. That state’s economy was damaged enough that officials thought it would take years to recover.
      https://notalotofpeopleknowthat.wordpress.com/2015/10/24/hurricane-patricia/

      And it is clear which storm was the stronger.

      • David A permalink
        October 26, 2015 8:14 am

        Exactly. 165 mph winds to not take weak poorly built roofs off. They flatten buildings and rip palm trees from the ground. There should be massive evidence of 165 plus MPH winds in the vegetation. I have yet to see any.

      • A C Osborn permalink
        October 26, 2015 2:16 pm

        The UK 1987storm had 115-120Mph winds and downed thousands of trees, including 6 of the 7 Sevenoaks trees.
        I can understand the Satellites getting it wrong as the measure at the top of the Hurricane, but how did the Aircraft get it wrong?
        Can a Category 5+ hurricane really be disipated that quickly, ie a matter of a few hours?

  2. October 25, 2015 9:25 pm

    Hurricane Patricia was investigated by reconnaissance aircraft when it was still well offshore and that was the most accurate source of information about the storm’s intensity. The aircraft found that the high wind core was very tight, with hurricane force winds extending no more than about 30 miles radius from the center. The eye diameter was quite small at about 5 to 7 miles and the highest winds were measured only a few miles beyond the edge of the eye in the eye wall. Thus the radius of extreme winds may have been only about 10 miles from the center. When the eye reached landfall, the only method for estimating the intensity at the time was satellite imagery, which can have a fairly large uncertainty compared to aircraft or ground measurements. The satellite imagery showed evidence of a weakening trend as the center approached the coast. Mountainous terrain along the coast undoubtedly helped to weaken the storm much more rapidly as it moved inland as compared to storms moving inland over flat terrain.

    I found an interesting website (that I have not yet fully explored) with good information about the various measurements that can be made to determine hurricane intensities:
    http://hurricanescience.org/science/observation/aircraftrecon/

  3. October 25, 2015 9:53 pm

    The Australian Bureau of Meteorology has exaggerated the severity of Tropical Cyclones.

    The Bureau gives the following list of strengths for Tropical Cyclones:

    Tropical Cyclone Category System
    CATEGORY 1 (tropical cyclone)
    Negligible house damage. Damage to some crops, trees and caravans. Craft may drag moorings.
    A Category 1 cyclone’s strongest winds are GALES with typical gusts over open flat land of 90 – 125 km/h.
    CATEGORY 2 (tropical cyclone)
    Minor house damage. Significant damage to signs, trees and caravans. Heavy damage to some crops. Risk of power failure. Small craft may break moorings.
    A Category 2 cyclone’s strongest winds are DESTRUCTIVE winds with typical gusts over open flat land of 125 – 164 km/h.
    CATEGORY 3 (severe tropical cyclone)
    Some roof and structural damage. Some caravans destroyed. Power failures likely.
    A Category 3 cyclone’s strongest winds are VERY DESTRUCTIVE winds with typical gusts over open flat land of 165 – 224 km/h.
    CATEGORY 4 (severe tropical cyclone)
    Significant roofing loss and structural damage. Many caravans destroyed and blown away. Dangerous airborne debris. Widespread power failures.
    A Category 4 cyclone’s strongest winds are VERY DESTRUCTIVE winds with typical gusts over open flat land of 225 – 279 km/h.
    CATEGORY 5 (severe tropical cyclone)
    Extremely dangerous with widespread destruction.
    A Category 5 cyclone’s strongest winds are VERY DESTRUCTIVE winds with typical gusts over open flat land of more than 280 km/h….

    During and since Tropical Cyclone Yasi in 2011 and Marcia in February this year, the Bureau stated the strength of these cyclones as being Category 5. Engineers from James Cook University’s Cyclone Testing Station examined damage from these systems and reported that damage caused by Yasi indicated “the maximum gusts over the mainland did not exceed 240 km/h” (Category 4) and TC Marcia indicated Category 1 in Rockhampton and Category 2 at Yeppoon.

    To read more about the total misreporting of Tropical Cyclone Yasi by the Bureau read my account here… http://www.onlineopinion.com.au/view.asp?article=17109

  4. Ben Vorlich permalink
    October 26, 2015 6:58 am

    I hope Harrabin and the BBC don’t find out about 1800 kp
    h windspeeds,they’ll certainly claim that as a worst ever. The MO will claim it must be correct because the air in the hurricane was well mixed.

    • October 26, 2015 12:34 pm

      But was it near the runways of a major airport?

  5. October 26, 2015 2:21 pm

    Reblogged this on WeatherAction News.

  6. October 26, 2015 4:48 pm

    The major damage was to banana plants which fall over if you look at them crosseyed.

  7. Tom O permalink
    October 26, 2015 7:08 pm

    And what of Hurricane Camille? The anemometer was reading 190 mph when it was destroyed by the storm. I always thought 190 was higher than 165 or 150 or 140 or whatever.

Trackbacks

  1. Patricia’s Wind Speeds At Landfall | ajmarciniak

Comments are closed.

<span>%d</span> bloggers like this: