Dramatic Downburst in Amarillo This Afternoon

By -
The National Weather Service's Amarillo office took quite a picture of a downburst at 4:02pm CDT this afternoon (hat tip: Mark Fox).

Here is the raw image.

It becomes even more impressive when the air flow is superimposed.

A downburst, discovered by Dr. Ted Fujita after his examination of the crash of Eastern Airlines Flight 66 in 1975, is an extreme hazard to aviation due to wind shear in both the horizontal and vertical.

On radar, nothing ominous is present on radar at 3:52pm.
click to enlarge
The black circle is the location of the radar at the airport. That is the location of the photo.
  • The left is the "reflectivity data" which depicts how hard it is raining. This is the type of radar display you typically see on television. 
  • On the right is the Doppler wind velocity data. Nothing unusual there, either. 
At 3:57, a core of intense rain, with some hail, makes its presence known (black oval, left). It is rapidly descending through the thunderstorm toward the ground. The rain may just be touching the ground at this time.
At right, the first sign of diverging winds (orange circle) is present. Green winds are winds blowing toward the radar and reds are winds blowing away from it. 

At 4:01pm, the downburst has struck the ground and is spreading out (wind flow shown by arrows at right). There is 69 mph of wind shear which would be enough to cause a plane crash if the downburst was near the end of a runway and a plane happened to be in the wrong place at the wrong time. 
The photo was taken one minute after the radar collected this data. 

The downburst is fully mature at 4:06pm.
Downbursts used to cause a crash every 18 months or so from the late 1960's to the 1985 (Delta 191). Fujita published his findings in 1977 but the aviation and meteorological communities were slow to accept the results, resulting in hundreds of needless fatalities.  

Fortunately, through the work of Dr. Fujita, Dr. John McCarthy, NW Airlines' Patrick Clyne and others, the last downburst-related airliner crash in the United States was nearly 26 years ago. However, they continue in other nations, including one in Mexico two years ago. 

The conquering of the downburst is another of the amazing successes of weather science the last 30 years. 

Comments

Post a Comment

Popular posts from this blog

The East Coast Severe Weather Threat is Over

By -
Image
Midnight: The East Coast Threat for Tornadoes and Severe  Thunderstorms Has Ended 3:50pm. Tornado watch for the Middle Atlantic Region. 2:30pm Tornadoes are also forecast in the South. 2:20pm. A couple of tornadoes, hail and wind gusts to 65 mph are possible with these storms. This includes NYC and Philadelphia.  1:05pm. The tornado risk has been extended northward into New York. The brown area has a significant risk of tornadoes. Remember: if a tornado warning is issued, go to your basement and get under heavy furniture like a pool table. Of, if your basement is finished, get into the bathroom. Go ahead an put a couple of water bottles and, if appropriate, diapers in your shelter area. Wear shoes.  If you don't have a basement or safe room, go to the lowest floor and get into a bath or closet in the middle of your home. Children should be put in the bathtub.  I'll update later today. 
Read more

Today's Tornado and Severe Thunderstorm Outlook - 9:30pm

By -
Image
After 65 mph winds went through Wichita, we have been without power for 35 minutes. So, I am going to have to end coverage for the night (using backup systems to write this). Scroll down for the forecast of tornadoes and severe thunderstorms for Sunday and Sunday night.  Please read down for the latest forecasts regarding this dangerous tornado and damaging wind situation! 5:40pm, a new "regular" tornado watch has been issued for north central Kansas.  Note that wind gusts to 80 mph are likely in this storm in addition to tornadoes and giant hail. Please make sure friends and relatives in the area are aware of the danger in the area outlined in red below plus the red area outlined at 2:50pm  In addition to "several strong tornadoes," hail to 4.8" in diameter is forecast along with wind gusts to 80 mph. Now is the time for persons living in mobile homes, manufactured homes and those with mobility issues should be making plans!!  Do not wait until a tornado warn...
Read more

Updated Freezing Rain and Heavy Rain Forecast

By -
Image
Note: An Updated Forecast is Available HERE Freezing Rain The National Weather Service has now issued winter weather advisories, two warnings and a watch. It may be a bit too large but, when it comes to freezing rain and slick roads, caution is usually the better course of action.  Here's a color code: Deep purple is an ice storm warning; serious condition where power outages are possible. Pink is a winter storm warning for significant icing. Deep green is a winter storm watch. I don't know why this is still a watch. If I were on the forecast desk I would have a winter storm warning for icing.  Dark blue is a winter weather advisory, a lesser condition, for icing.  Here is a view of the entire watch/warning/advisory area. The small area of green in Illinois is for flooding and, in Nebraska, for snow.  Here is a forecast of freezing rain amounts; totals to 6am Tuesday.  Color codes: Yellow is 0.25 to 0.50 inches. Power outages may occur in this areas. Deep blue i...
Read more