With rainfall running 15 inches below normal this year, December continued our trend of dry, uneventful weather, and there’s little reason to expect much change for the rest of this winter.
Unlike our annual trend of cooler-than-normal temperatures, December was much warmer than normal. Our average high was 59 while our average low was 43, giving us monthly average temperature of 51, which was 5 degrees above normal. For the year, we had six months which were cooler than normal, three months warmer than normal and three months near our climate normal.
Rainfall was dismal. As the month came to a close, Denton Municipal Airport had recorded less than a half inch of rain (.45″), making December our fourth driest month of the year. Normal rainfall for December is 1.46″.
Rainfall for all of 2014 was barely over 23 inches. Our normal annual rainfall averages 38 inches. Wow. The only thing that kept us from critical water shortages in some areas this year was the fact that we received nearly 15 inches in April, May, June and July, including 6.24″ during July, which was our wettest month this year.
The Western Drought has continued since fall of 2010. And while there are no particular forecasts that would indicate an end to the drought, most similar droughts tend to run their course in 3-4 years.
The National Weather Service Climate Prediction center indicates North Texas could be slightly cooler and wetter than normal during January, but the signals on which the longer-term forecasts are based are very weak. For instance, the long-predicted El Nino remains weak and slow to develop. If it were stronger, we could expect forecast sub-tropical Pacific lows and more frequent rainy storm systems from the southwest.
Taking an even longer view is even more speculative, but for what it’s worth, there are at least two significant factors to consider. First, solar output, which runs through multiple cycles between 11 years and thousands of years, appears to be at low ebb. Sunspot activity is sparse and slow-moving. Some climate forecasters believe the sun is at the beginning of a 206-year solar minimum, which produced a strong cooling trend the earth endured between 1793 and 1830. Second, the Pacific Decadal Oscillation appears to show a significant cooling trend in the waters of the northwest Pacific Ocean near Asia. Such conditions often foreshadow an extended period of cooler-than-normal temperatures in the Northern Hemisphere. Taken together, those two signals could indicate a cooling trend of 20 years or longer. But a word of caution: Trends and results of both solar output and ocean temperature are much easier to detect in hindsight than foresight. So, for that matter, is the weather.
Brad Barton is Chief Meteorologist of WBAP 820 / 570 KLIF / 99.5 “The Wolf.”
EDITOR’S NOTE: Just FYI, the recent 1.70 inches of rain we received in our area began on New Year’s Day.