Los Alamos, White Rock have mild month

-A A +A

November brought sunlight and a break from the cold

By Scot Johnson

October was cold and wet, but November was the opposite with dry and mild conditions throughout, save for two minor storms. Mean temperatures in Los Alamos were nearly five degrees above normal and the precipitation total at month’s end was merely one quarter of an inch, about one fifth of what we expect in November in Los Alamos.

Following two weeks of very mild temperatures and clear skies, November’s first storm arrived on the thirteenth. A low pressure system carried a cold front and some moisture from west to east across northern New Mexico. But as is often the case with winter storms from the northwest, we were not left with significant precipitation. The big winter storms usually come from the west or southwest where the warmer, moister air sees lower terrain until it reaches our higher elevations and is forced to unload.

High pressure followed the mid-month storm, bringing stability and clear skies but also cool air from the north. Temperatures steadily dropped from the 13th through the 15th. From there, temperatures rebounded to above normal until the second and last storm which arrived the weekend after Thanksgiving. As before, a glazing of snow and overcast skies were all that we had to show for it.

Despite a budding El Niño event in the tropical Pacific, precipitation was scarce over New Mexico in November. Los Alamos measured 0.26 inches of liquid equivalent and only 1.6 inches of snow. Los Alamos gets 1.19 inches of liquid on average in November as well as 5.3 inches of snow. White Rock fared better with .39 inches of liquid but still fell well below the average .93 inches there.

Temperatures were an impressive five degrees above normal in Los Alamos during November with an average of 42 degrees. The average maximum of 53 was also five degrees above normal. The average minimum of 30 was four degrees above normal. White Rock was closer to normal with an average of 40 degrees. The average high there of 56 was four degrees above normal. The average low of 24 degrees was right on normal.

As usual, White Rock had more extreme temperatures than Los Alamos with warmer temperatures during the day due to its lower elevation but also cold drainage flow at night. The cold flow overwhelms the relative warmth that White Rock would otherwise experience due to its lower elevation, and thus low temperatures in White Rock are almost always less than in Los Alamos.

Wind statistics were a bit interesting in November. The average wind speeds in both Los Alamos and White Rock during the month were about 10 percent higher than usual. The wind gusts, however, measured by the top gust every day and by the number of times gusts exceeded 40 mph, were lower than usual in both towns. This might be explained by the relative lack of storms and hence lack of gusts.

As has been reported since summer, El Niño conditions are present in the tropical Pacific and are expected to build into a moderate event this winter, which generally bodes well for good chances of snow here. The NCEP seasonal forecasts are finally beginning to include above average precipitation in the area beginning in January across most of New Mexico.

Scot Johnson is a meteorologist with the Waste and Environmental Services Division, Environmental Data and Analysis Group at Los Alamos National Laboratory.