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Weather Blog

Models need (and will get) improvement

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Two news stories about forecasting models caught my eye this week. The first dealt with a shortfall in the climate models and the second was good news about continuing improvements in our daily forecasting models.

I’ve written before about potential problems with initial data and assumptions in climate forecasting models – the ones used by climatologists to predict our global conditions decades in the future. Like it or not, they are not perfect.

NASA climate map

Credit: NASA, 2015. “NASA global data set combines historical measurements with data from climate simulations using the best available computer models to provide forecasts of how global temperature (shown here) and precipitation might change up to 2100 under different greenhouse gas emissions scenarios.”

Some researchers from Princeton University drove that point home with a recent paper in the journal Nature Communications. Jun Yin and Amilcare Porporato’s paper, “Diurnal cloud cycle biases in climate models” details how they carefully analyzed satellite data from 1986 to 2005 and compared the information they gleaned to what the models produce.  The two determined how the time of day that clouds form in reality versus the time of day averaged in the models can affect the amount of solar radiation the models predict.

In the climate models, the cloud cover peaks in the morning. In reality, the cloud cover peaks in the afternoon – the same time the radiation coming from the sun peaks. The amount of clouds and types of clouds between the earth’s surface and the sun make a difference in how much energy from the sun we receive. The climate models’ were over-estimating that amount and potentially forecasting hotter and drier conditions based on it.

The paper states, “Thus, on the one hand, consistent biases in DCC [diurnal cycle of clouds] between present and future climates give rise to similar TOA [top of the atmosphere] reference irradiance, so that the model tuning made for current climate conditions still remains largely effective for the global mean temperature projections. On the other hand, consistent biases have the potential to increase the uncertainty of climate projections.” In simpler terms, the researchers don’t think the temperature forecasts are completely wrong, but they have shown the margin of error may be much greater than most scientists have acknowledged up to this point.

The hope is for the results of the study to be used to improve the current models.

In another story, the National Oceanic and Atmospheric Administration (NOAA), released the news on Tuesday that they are in the third phase of a massive supercomputer system upgrade. This year’s improvements increase the processing speed to 8.4 petaflops and 60 percent more storage capacity. The added speed and storage will allow for more initial conditions data – extremely important information for forecasting – and higher resolution, which will help with accuracy with respect to geographical space and time.

The goal is to improve our forecasting capability, especially when it comes to warning of dangerous storms. The forecasting model specifically mentioned in the press release is the Global Forecasting System (GFS), which has a reputation among many forecasters of often being less than accurate more than two or three days out, even though it produces predictions for 10 days out. Improvements to the GFS are needed and quite welcome!

If you’re not a meteorologist or climatologist, you likely don’t know the frustration of making a forecast based on science and technology – much more than we had fifty years ago – and still knowing that there is a chance the models we rely on are missing critical input and getting it wrong. While most people may not consider a few degrees error in temperature a horrible thing, they’d probably agree when the temperature happens to be around 32 degrees, a few degrees in either direction can make a big difference in our weather reality.

Weather Blog

Long wait to see weather heroes worth it

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Hundreds of people of all ages stood for hours in a line queued around and inside the General Aviation Terminal at RDU International Airport Wednesday afternoon. Looking at it and listening to the chatter of the people in it, I was reminded of waiting to experience a popular ride at Disney World on a high traffic day. The afternoon heat combined with concrete helped create that memory as well, but RDU had something Disney would never offer — free bottles of water being handed out by Red Cross volunteers and RDU police officers.

Like Disney, with the exception of a few grumpy toddlers, everyone was in good spirits and quite friendly. Unlike Disney, we weren’t in line for a thrill ride in a theme park. Instead, we were patiently waiting to meet service men and women who get to live the ultimate thrill ride every year – the NOAA Hurricane Hunters!

With the exception of a few broadcast meteorologists, very few weather geeks receive the recognition and heroic welcome that these guys do. Part of it is the excitement of meeting the select few who pilot planes that fly through the eye wall of hurricanes, the specialists who drop meteorological instruments into the storms, and the mechanics that keep the planes in top condition for their important missions. The other part is the fact that they bring the planes for the public to see up close and in person.

I would never profess being an aviation geek. I am not even a fan of flying; although, I am a fan of traveling to far-off places and that often requires boarding a plane. Thinking about the job the Hurricane Hunters do from the perspective of someone who suffers motion sickness creates an even greater element of awe for them. I heard them asked by several people whether they have ever been ill during a mission, and all said “no.” Impressive.

big plane

From outside the terminal, a glimpse of the big plane hinted at just how big it really was.

For being the rock stars of the military and scientific research worlds, they were very approachable and friendly. They seemed to enjoy chatting about their lives and careers with perfect strangers.  A few even walked up and down the line soliciting questions from those patiently awaiting their chance to see the inside of the big plane.

Pilot Shannon Hailes stopped to chat with my section of line on the tarmac and offered to have his photo taken with us. I opted to just have him in the picture (the album is posted on my Facebook page), and asked him a few questions about his career and why he chose to be a Hurricane Hunter. Hailes told us that he has been in the Air Force since 1991 and used to fly combat missions. This week is his 26th anniversary of active duty. He chose to join the Hurricane Hunters for three reasons: they are based close to his home in Mississippi, he gets to help people by providing necessary data used to improve hurricane forecasts, and he was “tired of getting shot at.” We thanked him for his service — past and present — as he moved down the line.

After nearly two hours of waiting, I finally got to see the inside of the big plane, which is a WC-130J that has a few customizations specific to its mission including a radiometer pod on the left wing and two external fuel tanks that give it a longer flight range. I was impressed despite not really knowing much about planes. I could see where the crew sits, and I could see where the weather equipment lives. That is really all I wanted to see.

More interestingly to me was meeting the man whose job it is to deploy Dropsondes from the big plane. His name was Chris Beckvar, and he was inside the big plane answering questions. He told us that he has been doing it for six years. He used to be a carpenter and wanted to do something different. He enjoys helping to get information about the storm to the National Hurricane Center so that our Hurricane forecasts can be more accurate. Beckvar explained that he deploys 12 to 14 Dropsondes on a mission, three of four of which are deployed while flying through the eye wall, inside the eye, and back through the eye wall. They also drop the instruments outside of the hurricane in areas around it to find the steering currents to help forecast the direction of the storm.

I could probably spend all day writing more about the experience, but I have other work to do. Feel free to look at the album of photos from the afternoon on my professional Facebook page. For now, I will leave you with a few final thoughts:

  • If you have the chance to see the Hurricane Hunters in person, take it, but bring your patience. The experience is truly worth the wait.
  • While some of the day focused on educating school children, the real goal was to educate the public about this special group’s important mission.
  • The next time you hear or read a hurricane forecast, remember the brave people who fly through and around those storms in order to collect data that is absolutely necessary to making that forecast.

A few links for more information on the NOAA Hurricane Hunters:
http://www.hurricanehunters.com/mission.html (Dropsonde information)
https://www.facebook.com/NOAAHurricaneHunters/ (Like them!)