“The storm starts, when the drops start dropping
When the drops stop dropping then the storm starts stopping.”
~ Dr. Seuss



Well said, Dr. Seuss! He is definitely able to make the complex simple and also scientifically sound. Though he may be perfect for minute-to-minute weather observations, long-range predictions and forecasts are best left to the scientists. No disrespect intended for the father of The Cat in The Hat. While the names of famous scientists may elude us, never would that of Dr. Seuss.

One only has to look back at our weather’s recent rollercoaster ride to appreciate the complexity of weather science. Last Friday was cold with a brief but heavy rainstorm leaving 0.10 of an inch. By the first of the week, the temperatures, ushered by gusty Santa Ana winds, were on the rise.

Ever wonder how the National Weather Service meteorologists come up with their forecasts and predictions? There are many sources and, for those who are interested, quite fascinating. Intrigued by all things weather has led me to the same places the real weather people go – weather models. Forecasters, both scientists and amateurs, find weather models indispensible in their attempt to interpret the elusive behavior of Mother Nature.

We need some definition here. A weather model is based on a compilation of complex mathematical equations analyzed by state-of-the-art supercomputer technology. The entire process is known as “numerical weather prediction.” The key elements of weather observation used in these calculations have not changed dramatically since the 1800s. Included are temperature, moisture, barometric pressure, wind speed and direction at both the Earth’s surface and also vertically through the atmosphere. Over the years the methods to disseminate weather information has drastically changed, both in terms of reliability and advanced technology.

I wait until the very last possible minute (usually mid-Wednesday afternoon, as the CV Weekly comes out on Thursday mornings) to make my final observations and weather prediction for the upcoming week. More often than not, my accuracy is surprisingly impressive. A fun self challenging activity, to be sure! I do rely on several sources, including the various weather models. The top three are:

GFS (Global Forecast System) – A forecast model run at NCEP. It is run four times daily, with forecast output out to 384 hours. Coverage area is global-wide.

NAM (North American Meso) – A model run four times per day, forecast ability out to 84 hours. Covers primarily North America.

ECMWF (European Center for Medium Range Weather Forecasting) – London based model. Runs twice a day. Coverage area includes North America and Europe.

Meteorologists have their favorites ranging from the small university based to one run by the U.S. Navy out of Monterey, California. Of the well known, the ECMWF is favored in accuracy and is considered the worldwide gold standard. It seems the U.S. has some major catching up to do to Canadian and European models. The problem is inadequate computer power. The fault is a political one; our scientists are first rate!

*With respect to scientists in the field of meteorology, the above information was summarized by an amateur weather watcher.

Now, the Seuss model for the weather: “The wind gets windier and the hot gets hotter” through Thursday. By the weekend and into next week, a significant change is expected. Cool temperatures accompany fog and low clouds over much of California. By Monday/Tuesday a light rain may fall over the Crescenta Valley. The time for April showers has passed.

Enjoy the May flowers and perhaps a late spring shower.

Sue Kilpatrick is a Crescenta
Valley resident and Official Skywarn Spotter for the National Weather Service. Reach her at  
suelkilpatrick@gmail.com.

  Sue Kilpatrick