January breaks records for frigidity

-A A +A
By Scot Johnson

January’s weather was unexpected in many ways. The mean temperature was 5 degrees below normal and a mere 2.8 degrees warmer than the coldest month ever measured in Los Alamos: January 1930. January was wetter than normal, also unexpected since the strong La Nia conditions in place were supposed to reduce precipitation this winter. And January was windy, a condition we don’t expect until spring.The interesting weather began around Jan. 7 when a southwest-to-northeast moving system pushed out of Arizona and into New Mexico, not unlike the storm earlier this week. The storm delivered only a glancing blow to Los Alamos but favored the Jemez and left Los Alamos with more than 7 inches of snow. The storm was followed by a series of cold fronts, hitting in succession to turn cold days into even colder days. The strongest cold front came Jan. 15 along with sustained northwesterly flow that drove the high temperature on Jan. 17 below the day’s normal low temperature.The final week of January brought a series of two similar storms, both of which dropped along the Pacific coast and then crossed the southwest traveling west to east. The first storm was cold and dry. The second was warmer but brought enough moisture to catapult the month’s total precipitation beyond normal. This storm also brought damaging wind gusts, which lasted, off and on, for three days.At month’s end, January’s average temperature was 24 degrees in both Los Alamos and White Rock, when the normal is 29 degrees in both towns. Record low temperatures were set in Los Alamos on Jan. 16-17. The reading of minus 4 degrees on Jan. 17 was an impressive 8 degrees below the previous record for that day, set in 1947. White Rock fell even further to minus 6 degrees that morning, breaking the record there by 2 degrees. The all-time low record in Los Alamos, incidentally, is minus 18 degrees, recorded Jan. 13, 1963. Wind chill is not included.The total precipitation count for January was 1.39 inches in Los Alamos, 45 percent more than the normal 0.96 inches. White Rock’s total was 1.02 inches, 65 percent above the normal 0.62 inches there. Los Alamos collected 7.6 inches of snowfall in January, about half the normal 14 inches.The average wind speed in Los Alamos during January was more than seven miles per hour, about 50 percent above normal for Los Alamos and typical of April through June, the windiest months of the year. White Rock’s average was 20 percent higher than normal. The strongest gusts of the month followed a cold front Jan. 28.Gusts in Los Alamos reached 60 mph at about 7 a.m. Jan. 29, felling trees all over town. Gusts in White Rock topped out at 49 mph. The moderate La Nia event in progress in the tropical Pacific was expected to bring warm and dry conditions to New Mexico this winter, but the correlation between our weather and El Nio / La Nia is far from unity.With that in mind, take the Climate Prediction Center’s continued prediction of a warm and dry spring with a grain of salt.There are other modes of climate variability in the mix that are not well accounted for. The Pacific Decadal Oscillation might have an even stronger influence on our weather than El Nio /La Nia, but its dynamics are not as well understood, nor is it as predictable. The Madden-Julian Oscillation, which acts on the relatively short timescale of weeks and months rather than years or decades, has been given some credit for our unexpectedly wet winter.

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