Monday, September 29, 2008
Weather columnist Kevin Myatt: Long-range computer modeling came through in predicting rain system
Kevin Myatt is The Roanoke Times' weather columnist.
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This week's coastal low that moved inland and soaked us was a success story for sometimes-maligned long-range computer modeling.
For most of the past two weeks, long-range computer forecast models were consistent in developing a strong low-pressure system somewhere near the Southeast U.S. coast.
The details of the system, including location and timing, varied as different models spit out several new solutions each day. Sometimes, it showed up as strictly a low-pressure system forming with the help of an upper-level low and a stalled front; sometimes it appeared to have tropical characteristics, or incorporated the system that has since become Hurricane Kyle far off the East Coast.
But run after run, different forecast models showed the storm in a similar location. National forecasters highlighted the East Coast for high wind and waves many days before the storm even formed.
By early last week, the models began to show that the system was going to take a track farther west rather than just hanging along the coast. It ended up coming ashore a little farther south, moving inland a little farther west and moving a little slower than earlier projected. Some models gradually caught on to what was happening.
So that's how a remote chance of showers turned into a three-day intermittent rain. The computer models painted the broad strokes of the weather pattern well, but needed some last-minute touches to fill in the details.




