Specific factors mixed to give Laredo white Christmas

By Juan Alanis

What were the chances of a white Christmas in Laredo? I would have probably told anyone asking that they were crazy to even think it could happen. Snow at any time during the year would have been a very rare occurrence in Laredo and South Texas , let alone the idea of a Christmas snowfall.

“This was a very historic snowfall for Christmas Day in deep South Texas ,” reported meteorologist Jason Straub of the National Weather Service (NWS) in Brownsville . Historic indeed, as the snowfall made headlines across the nation on CNN, the Weather Channel, and in newspapers from Texas to Puerto Rico 's El Nuevo Dia. This was the first white Christmas for all of the region and the first measurable snowfall in decades for many areas. According to data from the NWS, most of Webb County received two to four inches of snow; Hebbronville, five inches; Freer and Encinal, six inches; Zapata, one inch. This was the Gateway City 's first measurable snowfall since a three-inch snowfall in 1973. In the Rio Grande Valley , Brownsville 's 1.5 inches was their first snow since 1895.

The cause of this event was a mix of circumstances that rarely come together this far south. First an Arctic cold front brought us very cold air on December 23. High temperatures went from the 70s to the 40s, with lows dipping to freezing. Then a strong upper atmospheric disturbance moved through the region late on the 24th. This “wave” in the atmosphere forced moisture to rise, condense, and then fall as snow. On Christmas Eve, snow flurries began early in the afternoon, though they did not last as temperatures were still above freezing and the moisture content near the ground was still a bit low. Plus, the upper level disturbance had not yet arrived in the area.

NWS metereologist Jennifer Salato who is stationed in Corpus Christi said that timing was crucial. “We knew there was a possibility [of snow], but were not sure if all factors would come together at the right time,” she said. As Laredo and South Texas found out later in the evening, the necessary ingredients came together perfectly -- the upper-level disturbance, increased moisture at the surface, and freezing temperatures at all levels of the atmosphere and surface came together perfectly to reward Laredoans with a first-ever White Christmas. “This definitely was a rare event for South Texas ,” Salato added. In most cases, when an Arctic front comes to South Texas, all the moisture is cleared out, which results in those calm, clear freezing nights to which we are accustomed.

Whether or not the weather phenomena El Niño was a contributing factor to the snow has not been determined. “One storm itself is not an indicator, but data over an entire season can indicate this,” Straub said. He added that current data indicates we may be in a weak El Niño pattern.

Will we have another white Christmas, or snow at all, in 2005? It's hard to say. Based on long term trends, however, it would be very, very unlikely -- say the same odds as the Boston Red Sox or the Chicago Cubs winning back-to-back World Series Championships. Rainfall and cooler temperatures, however, still are in the picture. According to the NWS Climate Prediction Center in Maryland, the outlook for January, February, and March is calling for a decent chance of above average rainfall, and a slight chance of cooler temperatures. Remember, this is just an “outlook.” Most of us in the world of weather agree that forecasts beyond 14 days out are usually just educated guesses based on data and patterns observed in the last 100 plus years.

The year 2004, though, was cooler and wetter. Laredo received 27.22 inches of rain last year, according to KGNS-TV meteorologist Richard Berler. This was seven inches above the normal, though it does not even rank among Laredo's five wettest years. Summer temperatures were also cool compared to what we normally have. Most Laredoans know it feels like an oven all summer, but 2004 was the coolest, with the least number of 100-degree days in two decades. I know 99 percent of Laredoans were not complaining about the lack of 100-degree heat.

We will see what 2005 has in store for us. Perhaps continued above normal rain and cooler temperatures.

(Weather observer Juan Alanis, Jr., is an Associate Member of the American Meteorological Society and is currently employed as a teacher at Los Obispos Middle School.)