Weather reports get to the point
If you're planning an outdoor event somewhere in Hawaii and want to know what the weather will be like at that location, you can find out on the National Weather Service's Web site, weather.gov/hawaii.
Since 2004 the NWS has refined forecasts down to a smaller scale and more specific areas, Bob Ballard, Honolulu Forecast Office science and operations manager, said in an interview.
After last year's torrential March flooding, people were asking how much rain to expect -- would it be heavy or drizzle -- so they could fix their roofs or make other repairs, he said.
Forecasters were able to say whether it was likely to be dry at their location or whether there was a low or high probability of rain, he said.
"In the past, we might say there would be isolated windward showers, but we didn't tell people the level of detail of what's going to happen at their location or the area they're interested in."
In 2000, Ballard said, "we were pretty much doing one forecast for each island and brief forecasts for three zones on the Big Island. In 2002 we went to a bunch more zones."
The meteorologists are now using software to create a forecast covering 20 or more elements, he said, such as minimum and maximum temperature, sky coverage, precipitation probability and wind direction, speed and gusts.
"For people interested in doing prescribed burns or fighting wildfires, we can provide parameters useful to them in trying to get a handle on fire behavior and what's going to happen," Ballard said. "They relay on weather elements to figure out where the fire is going and what areas might be threatened. It's much more specific than we could ever be in the past."
Instead of one forecast for Oahu, the "graphical forecast editor" software looks at 258 grid points on the island, he said.
Someone doing a prescribed burn or planning a garden wedding, camping-out trip or barbecue can click on one of the grids and get a specific forecast.
There is a map on the front page of the Web site and a box with latitude and longitude, Ballard said, "so if you had a GPS, you could figure out what our forecast was for that particular location." Information is available for any place in the islands or within 40 nautical miles.
"That doesn't necessarily mean the forecast is more accurate, but it does mean we can be more precise for that location instead of saying, 'The area looks wet,'" Ballard said.
"We can say (for example) that there is a 40 percent chance of showers and one-quarter to one-half-inch of rain."
The system is being used at 122 weather forecast offices across the country, he said. "We're starting to see the benefits and trying to demonstrate what's out there for people."
Meteorologists also are trying to get more data for forecasts and computer models "to give us a better idea what's going on," Ballard said.
"A big part of weather forecasting, probably the most important part, is taking and collecting observations," he said. "If we don't know what happened in the past, we certainly can't make a forecast of what's going to happen in the future.
"We're constantly looking for ways to improve, doing research and studies on how we can make forecasts better," Ballard said. "That was a big leap we made a couple years ago."