Weather Smarts from DT

Information Floods Foreseen

Some of the abundant weather data we get now was rare or difficult 20 years ago...

  • Ocean subsurface temperatures. Buoys in the Pacific detect water temps and allow faster and more accurate tracking of El Nino and La Nina development
  • Current soil moisture indexes
  • Rates of rainfall. The rate of rain falling per hour used to be done by human observation, but now is measured using radar and other scientific measurements.

-- David "DT" Tolleris, Meteorologist


Today's Forecast

I suppose other fields of study around the world have evolved more than meteorology, but it is hard to imagine. Technology has had a significant impact on meterology. Twenty years ago, weather information was much more limited. Weather maps around the country--those simply reporting actual observations--didn’t come out as often, and took much longer to produce. A lot of the analysis was still being done by hand; the data was just starting to be transferred over to very simple computers.

Today, surface weather maps are produced every hour on the hour across every portion of North America. It is done by computer and it's done with more clarity and precision than any human could possibly do on a regular basis. In fact, a lot of the meteorologists that used to do the surface map analysis (by hand) have moved on to do custom weather analysis for private customers, such as grain companies. The challenge now isn’t getting the weather data or building the models ... it’s understanding what to believe, and when.

-- David "DT" Tolleris, Meteorologist


Extreme Weather Outlook

Much of the old work of the human meterologists has been handed to computers, so now computerized observation sensors can be put in a lot more locations, and in much more difficult--even hostile--environments. (North Pole, anyone?) You do have to train folks to maintain and repair the sensors, a new occupation that didn’t exist before. One thing hasn’t changed for meterologists: They still have to stick their necks out.

-- David "DT" Tolleris, Meteorologist


Updated Forecast

I advise other meteorologists in the energy and the grain fields--as well as serious traders--that the only way to get around the flood of instant weather data is to remember that the initial assessment is sometimes right... and sometimes quite wrong. In some cases only an experienced meterologist can spot flaws or conflicts that mean a report or model is not credible

-- David "DT" Tolleris, Meteorologist


Global Climate (Sensor) Changes

The automated computer sensors in use now can detect rates of snowfall, rainfall, and wind--plus wind gusts and barometric pressure--more accurately than ever. They can also measure deep sub-soil moisture and temperatures. The sensors are also global: You can now get instant, current (not one-week-old) weather data--including high-resolution radar and photos--from all crop areas of the world. The big challenge remains: Knowing how to use it.

-- David "DT" Tolleris, Meteorologist


Significant Weather Events

Here are some of the major advances in weather technology since the 1990s...

  • Doppler Weather Radar now allows us to look inside storms, get accurate rainfall estimates, and make more timely tornado forecasts.
  • The European weather model came out in 1991 and now allows accurate forecasts up to seven days in advance.
  • Early hurricane detection: A 5-day hurricane forecast today is more accurate than was a 48-hour forecast in 1991.
  • Many radio and TV stations have high resolution local radar available 24 hours per day.

-- David "DT" Tolleris, Meteorologist


Fast-Moving Weather Alert!

One benefit of technology is now I can send out forecasts via e-mail, as well as receive new weather data as soon as it is available. However, that speedy access to data causes problems, too. During the mid-day hours, one of the most important weather models released is the 12z GFS model. This can be very important during crucial weather events, whether it's a drought in South America or Texas or the threat of extreme heat in Iowa in July. I have seen a pretty strong reaction in the trade to the GFS model within seconds after it has come out... even before any sort of analysis has been done by meterologists (who could say whether the model is worth worrying about...or not).

-- David "DT" Tolleris, Meteorologist



About David Tolleris

David Tolleris

David Tolleris ("DT" to his friends and clients) is an energy and agricultural meteorologist based in Richmond, Virginia. DT graduated from City College of New York in 1989 and worked for several private weather forecasting firms in New York City and Hartford, Connecticut. In 1994 he joined the National Weather Service. In 1998, DT left the Federal Government to take care of his new son and to start his own weather business. Since then, DT has been forecasting for energy and agricultural companies. DT’s website,, is a very popular and well-known source of weather information for farmers, energy traders, and ag traders all around the world. "It's no-nonsense, no-BS information," says DT. He issues numerous reports daily, weekly and monthly via his website, with a special emphasis on 30-day forecasts and overseas ag concerns.

DT deliberately does not provide ANY trading advice. Instead, he focuses exclusively on his weather forecasts. “Which, believe me,” he says, “is plenty hard enough to do.” DT is a US Navy Veteran, a baseball fan, and a diehard, fanatical supporter of the Philadelphia Phillies.