Wednesday, August 27, 2014

Issues With National Weather Service Dissemination

Over the past two years, the National Weather Service — the agency tasked with issuing life-saving severe weather watches and warnings across the country — has had a bevy of technical glitches that have severely impeded its operations.
These incidents, which have ranged from the apparent issuance of a massive (and false) flood watch for all points east of Lake Michigan and north of Florida, to letting a tornado go essentially unwarned due to failures of automated systems, have the attention of the agency's leadership, the NWS says.
Andrew Freedman has the full story, with a comment from yours truly, here.

7-Day Rainfall Forecast

Generous rains are forecast the next seven days in the Upper Midnest.
The monsoon takes a break in the Southwest and needed rains fall in the Great Plains.

One caution: The area from Lincoln to Omaha to Des Moines/Ames, which has experienced some rain the last few days, have a flood risk if this forecast is exactly correct.

Tuesday, August 26, 2014

Monday, August 25, 2014

How Does a Major Earthquake Affect Sleep?

Answer here.

Rainfall From Now Until Friday Night

The heavy rains, which have caused considerable flooding, have ended in Montana. Over the next five days, heavy rains fare forecast for Nebraska and Iowa.

Time to Turn the Tables

There are whole university "centers" for studying how to convince the public and scientists like me that global warming is an immediate, catastrophic threat. So, I thought it would be fun to turn the tables and link to a psychological study that helps explain why, for example, the global warming cult gets more 'confident' as the science gets less definite. The entire story is here.

A reasonable reading of these results is that a lot of environmentalists experience many aspects of the modern world as chaotic and thus seek to compensate for their perceptions of disorder by engaging in ritual behaviors that make them feel like they are exerting more personal control. It is not much of a leap to conclude that by imposing those rituals on others, some environmentalists seek to reduce their dread of disorder even more.
Why call them rituals? Because it is not all that clear that they actually do anything much for the natural environment. For example, the costs of curbside recycling often outweigh purported benefits, and lower organic crop yields mean more land taken from nature.

Sunday, August 24, 2014

Thunderstorms and Towering Cumulus = Spectacular Kansas Sunset

There is zero color correction or special effects in this photograph taken just a few minutes ago from the Smith House in northeast Wichita.

There is an area of small thunderstorms to the southwest of Wichita (arrows) and these are towering cumulus clouds along the cold front north of the storms. 

Tornado Near St. Cloud, MN

Both radar and tornado image (courtesy of SevereStudios ) are from 6pm CDT.

The Doppler winds at 5:55pm when the tornado was forming. The tornado location is the circle and the arrows indicate the direction of the "mesocyclone" -- the winds surrounding the tornado.

How Fast Can Tornadoes Move?

There was a recent online discussion about the maximum forward speed of tornadoes. We've known for many years that 70-75 mph has been achieved on a number of occasions. The above Empire, Alabama, tornado was moving faster than that. This is why it is important, especially in February through April tornado situations, to keep up on warnings during tornado watches. Storms can move into your area very quickly.

Also, I often get asked if tornadoes can go up and down mountains. The video clearly shows it moving down a mountain.

Tornado Watch: Minnesota and NW Wisconsin

This is in effect until 11pm Central time.

Thunderstorms, as of this 3:49pm radar scan, are developing across the area.

Sunday Fun: Forecaster Evie Teaches Physics

Remember high school physics and the "inclined plane"? 
For today's generation of high schoolers beginning the fall semester, Forecaster Evie provides this demonstration of the utility of the inclined plane.
  1. Evie wanted pizza put into her bowl. To make it easier to get the pizza, you see her assess the situation.
  2. She decides the best way to get her bowl to the pizza is to use an inclined plane.
  3. Her first attempt is unsuccessful because she is grasping both the box and the bowl. She chuckles at her mistake.
  4. She deliberately repositions the bowl and creates the inclined plane.
  5. The bowl reaches the pizza for loading. She chuckles at the success of her plan.
Of course, in physics class they talk about loading trucks, railcars, etc. Evie prefers the simpler approach and uses a bowl for this demonstration. 

Have a great school year!!!

Saturday, August 23, 2014

Tropical Storm Looming

The National Hurricane Center is monitoring a tropical depression headed for the Bahamas. It is forecasting the depression to reach hurricane strength (where you see the "H") symbols. People in the Southeast coastal areas should keep an eye on the storm it will take probably another twelve hours (i.e., Sunday morning) before we can get more confident on the path/intensity.

Note: This is the storm the meteorological rabble-rousers were forecasting to hit New Orleans at one point last week.

South Dakota: Tiny Tornado Watch

This watch is in effect until 10pm. Please keep an eye out for any approaching thunderstorms. If they approach, please monitor weather radio or local media.

Note: I'm very pleased the NWS Storm Prediction Center issued this small, short-duration watch. I believe this is a direction they need to move as we get better at identifying geographically small tornado threats.

Tornado Threat in Northern Plains

Five percent is the significant threshold. People in the five and ten percent areas should keep a close eye on the weather if thunderstorms approach.

There is also an increasing flooding risk over the week and first of next week.

Views of a Kansas Microburst

Storm chaser Beth Bowdoin nailed a microburst in Reno County, Kansas, yesterday afternoon. She kindly agreed to allow me to use them.

The first shows the downburst descending from the cloud.

The second photo shows the globule of torrential rain almost to the ground. Because the storm is moving from left to right, the rain takes a tilted appearance. During this time cloud-to-ground lightning (not shown in the photos) picked up in frequency. This is common with downbursts.

The third photo shows the microburst made it to the ground and the winds began to spread.

Photo number four has the downburst spreading and a reinforcing globule descending.

I've increased the contrast to show the wind flow in the above image. The circle shows the horizontal rotation as it falls to earth.

The final image shows the reinforcing globule almost to the ground with the original microburst continuing to spread.

Here is a diagram of the winds with the final image.

I captured the National Weather Service radar at the time downburst was spreading out near Pretty Prairie. The most intense downbursts often occur along boundaries, in this case the boundary of rain-cooled air from earlier thunderstorms the 100° ambient air

Eleven minutes later, the Doppler velocity data shows the wind flow after the microburst has spread out. I've circled the northern (second) extension of the microburst. The greens are winds blowing toward the radar and reds away from the radar which is located at Wichita's Mid-Continent Airport.
The peak wind that I saw was near 50 mph. That might not be exact.

Downbursts are an extreme hazard to landing and departing aircraft. If you wish to learn more about them, please see Anatomy of a Microburst, the second all-time most popular posting on this blog.

Thanks again, Beth. Great photos.