{"id":25448,"date":"2020-01-26T00:00:11","date_gmt":"2020-01-26T08:00:11","guid":{"rendered":"http:\/\/stormbruiser.com\/chase\/?p=25448"},"modified":"2020-01-29T21:50:07","modified_gmt":"2020-01-30T05:50:07","slug":"january-26-2020-analysis-of-weather-conditions-in-calabasas-leading-to-the-kobe-bryant-helicopter-crash","status":"publish","type":"post","link":"https:\/\/stormbruiser.com\/chase\/2020\/01\/26\/january-26-2020-analysis-of-weather-conditions-in-calabasas-leading-to-the-kobe-bryant-helicopter-crash\/","title":{"rendered":"January 26, 2020 Analysis of Weather Conditions in Calabasas Leading to the Kobe Bryant Helicopter Crash"},"content":{"rendered":"

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At about 9:45 a.m. PST on Sunday, January 26, 2020, a helicopter carrying Kobe Bryant and his daughter, six friends and a pilot, crashed into a hillside in Calabasas, California. \u00a0The flight was headed from Santa Ana to Camarillo for a basketball game in Thousand Oaks. \u00a0It appears likely that poor weather and poor flying conditions were a big issue with regard to the crash, as heavy clouds and fog were in the area. \u00a0Since I grew up in nearby Woodland Hills and now live in nearby Westlake Village, and I am very familiar with the area and the local weather. \u00a0(I was the cooperative weather observer for the NWS in Woodland Hills for almost 20 years, and have been the weather observer in Westlake Village for 6 years!) \u00a0This study will look at the local weather conditions around the time of the crash.<\/p>\n

A weather system was moving roughly from the WNW to the ESE through Ventura and Los Angeles counties during the late morning. \u00a0The system was rather weak this far south, though, and little or no rain was expected with it. \u00a0The system was acting on a somewhat deep layer of marine air, which had spread into the coastal and valley areas of the two counties in advance of the weak weather front. \u00a0I was working as weather observer during the morning at San Nicolas Island Airport (KNSI), about 80 miles south of the incident, and during the morning the ceiling decreased from about 500 feet at 7 a.m. to 200 feet between 9 and 10 a.m. \u00a0The elevation here is 500 feet, so cloud bases were well below 1000 feet above sea level. \u00a0The visibility at San Nicolas Island airport dropped to under one mile, and there was light drizzle around 10 a.m. \u00a0Conditions gradually improved after 11 a.m. as the ceiling got a little higher. \u00a0The conditions at San Nicolas Island provide an idea as to the behavior of the cloud ceiling during the morning out over the ocean with the “front,” uninfluenced to a large extent by land. \u00a0 The elevation of the crash site in Calabasas is around 1100 feet.<\/p>\n

San Nicolas Island (elevation 504 feet)<\/strong> observations:<\/p>\n

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The numbers above show the date and time, the temperature and dew point (e.g., 54F and 52F at 6:53 a.m.), the relative humidity (93%), the wind direction and speed in miles per hour (NW 16 mph), the visibility (10.00 statute miles), any weather (such as fog, drizzle, mist), the sky condition (OVC005 means an overcast layer at 500 feet above ground, BKN009 means a broken ceiling at 900 feet), and the station pressure and sea level pressure and altimeter readings.<\/p>\n

Keep in mind that the helicopter pilot was planning on following the Ventura Freeway (U.S. 101) westward from Woodland Hills through Calabasas and Agoura. \u00a0(A handy-dandy map of this area is below.) \u00a0The terrain changes quickly from generally flat in the southwestern San Fernando Valley (where Woodland Hills is) to very hilly in Calabasas and Agoura. \u00a0The freeway rises up from elevations near 900 feet in Woodland Hills to about 1150 feet on the Calabasas Grade, down to 800 feet near Las Virgenes Road, and then back up to 900 feet on the east side of Agoura. \u00a0On both sides of the freeway, in close proximity, are hilltops from 1500 to 1700 feet in elevation, or about 500 to 900 feet above the freeway. \u00a0If you are flying through here and are not sure where the freeway is, then you had better be above 1700 feet elevation! \u00a0It is not unusual to see air traffic using this corridor with the freeway as a guide.<\/p>\n

Let’s look at some other airport observations for Sunday morning, starting with Camarillo (KCMA), on the Oxnard Plain and about 25 miles west of Calabasas.<\/p>\n

Camarillo Airport (KCMA), elevation 75 feet<\/strong><\/p>\n

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Camarillo Airport was the destination for the flight. \u00a0This airport is on a low coastal plain, at an elevation of only 75 feet above sea level. \u00a0The cloud ceiling increases slowly during the morning, from about 1300 feet at 8 a.m. to 1600 feet at 9:o5 a.m. \u00a0the visibilities aren’t too bad at all, and flying conditions are VFR (good!) since the ceiling is above 1000 feet and the visibility is 3 miles or greater. \u00a0Note that the wind shifts from ESE at 10:55 a.m. to SW at 11:55 a.m., and the visibility improves, suggesting a frontal passage.<\/p>\n

This next one is for Point Mugu<\/strong> (KNTD, elevation 10 feet), on the coast and maybe 7 miles SSW of Camarillo Airport:<\/p>\n

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Visibilities are also good at Point Mugu, but the ceiling is about 200 to 400 feet lower compared to that at Camarillo before 10 a.m. \u00a0The observer at Point Mugu also entered a “few” low clouds at 800 and 900 feet. \u00a0At Oxnard Airport, west of Camarillo, the sky and visibility conditions were quite similar to those at Camarillo. \u00a0The observations at Point Mugu were taken by an observer, and the cloud heights are estimates because the ASOS (weather instrumentation) was inoperative at the time. \u00a0I know this because I also work part time at Point Mugu Airport, and I spoke with the observer there around sunrise. \u00a0The observations from Camarillo and Oxnard were automatic, unless the air traffic controllers “augmented” the observation, which is not typical.<\/p>\n

And lastly, here are the observations from Van Nuys Airport<\/strong>, elevation 797 feet:<\/p>\n

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At Van Nuys, the visibilities were rather poor (about 2.5 miles), but they were certainly adequate for a helicopter that was flying just beneath a ceiling of 1100 feet. \u00a0A weather condition of “mist” is given when the visibility is under 7 miles and the temperature-dew point difference is less than five degrees. \u00a0It doesn’t necessarily mean that misty precipitation was occurring.<\/p>\n

Around 9 a.m., the helicopter was in a holding pattern near Glendale because of other air traffic. \u00a0If the helicopter pilot were checking these airport weather observations for 9 a.m., he might have not been too concerned about making it through the hilly Calabasas and Agoura corridor, as the ceilings at Van Nuys and Camarillo seemed to be sufficiently high. \u00a0Sufficiently high, that is, if the ceilings were no different between Van Nuys and Camarillo. \u00a0If the pilot had looked at the Point Mugu cloud report, and if he knew that the freeway was as high as 1150 feet elevation through the Calabasas Grade and he knew that the hilltops were several hundred feet higher (which I am almost certain that he did know), then any comfort level provided by the ceiling reports at Van Nuys and Camarillo airports would have, or should have, diminished considerably. \u00a0 Point Mugu is adjacent to the western end of the Santa Monica Mountains. \u00a0With a ceiling of 1200 feet above sea level there, that would not provide enough room at all to make it through Calabasas and Agoura, by going visual, under the overcast, if the ceiling and overcast layer were the same (relative to height above sea level) as at Point Mugu.<\/p>\n

Lets take a look at the visible satellite \u00a0images:<\/p>\n

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