Storms return to Ruidoso
The winter was wet, but not as good as forecasts and a warm and dry March wiped out the mountain snowpack
A high pressure ridge nicknamed "the blob" robbed southern New Mexico of much of its anticipated precipitation over the winter and early spring.
"We haven't gotten 10 percent of the precipitation we thought we would get from mid-winter until now," Thomas Bird, a meteorologist with the Santa Teresa office of the National Weather Service's El Paso Area. An incident meteorologist, Bird goes out with teams when they work large wildfires and hurricanes like Katrina, but primarily is a liaison between the NWS and land management agencies.
"I try to give them preseason assessments of what the fire season looks like, so they can better prepare," he told Lincoln County commissioners during a presentation Tuesday in Carrizozo, where he explained why the winter precipitation didn't live up to expectations.
"Last October, the Climate Prediction Center issued a forecast for December, January and February for a huge probability this area would be wetter than normal," Bird said. "We were just barely at normal. The reason the forecast was for wetter than normal was the El Nino, which is not a weather phenomenon. It is the state of the sea surface temperatures in the Pacific Ocean. Above normal is the definition for an El Nino. There is a big correlation between the sea surface temperatures in the Pacific and what kind of precipitation we get down here in southern New Mexico.
"When it is a warm phase, you typically have a wet winter. It peaked in the beginning of winter and has been steadily falling down into our spring. At one point, we were 3.5 degrees above normal, which is the strongest ever on record. So we were really pumped for a wet winter. Right now, we've dropped back to about 1.5 degrees, so we are trending back down to neutral."
Usually with an El Nino, the jet stream off the Pacific Ocean comes in flat and persistent, creating a strong track that brings in a succession of storms.
"But to the north along the West Coast of the United States, the sea surface temperatures also were above normal," he said. "We called all of that 'the blob.' That is why it wasn't considered in the forecast and why we think we didn't get all of the precipitation we were expecting this winter, because that was in effect. That blob dissipated and it's pretty much back to normal and that's why we've changed our pattern.
"Think back to February and March, the dryness and above normal temperatures. In the last two weeks, we have broken that pattern and we've started to see storms coming through and a little bit of precipitation."
Climate experts think "the blob" changed the pattern from El Nino back to La Nina (colder temperatures in the Pacific Ocean, dryer weather in New Mexico) and moved the jet stream north, and that was the reason the heavy precipitation didn't materialize, Bird said.
"So the storms (didn't) track through this area, they tracked north, and they (received) the rain and we stayed dry," he said.
An El Nino usually bring about 150 percent of normal precipitation in the Sacramento Mountains, he said.
"We should have gotten a really wet winter and should follow that with a fairly wet spring, but remember spring is the driest time in the Southwest, so extra precipitation doesn't mean a lot, just more than you would get in a given normal year," Bird said. "The forecast is for these temperatures to come back to normal by the time we get to the end of spring and our monsoon season. So that means we won't have El Nino or La Nina, it will be neutral."
The snowpack in the mountains is a type of savings account for moisture for areas such as Ruidoso and Carrizozo, he said.
"It keeps (moisture) into the spring when we dry out and helps the fuels stay more moist and keeps the fires down," Bird said. "It makes it harder to have the huge fires like we had in Little Bear (in Lincoln County in 2012).
"Early on in February, after the December and January snow, we were looking good at 150 percent of normal snowpack. In February, our snowpack was double the depth compared to 2015. It was over 200 percent of normal in January and 140 percent in February in the Rio Hondo Basin."
After the warm March, a lot of data is missing. The stations quit reporting, because there was no snow depth to report, he said.
"So all that savings account we had in the form of snowpack in the mountains we were hoping would melt out slowly during the spring, melted prematurely, because we had such a warm and dry February and March," Bird said. "What a difference a month can make. We're not supposed to melt that snow out this fast. Snow depth is supposed to peak right at the beginning of April in a typical winter and here we are in March with zero."
In April, the huge ridge sitting off the West Coast that was keeping all of the storms moving to the north broke up, he said.
"That ridge broke and started allowing storms to move back through us again, as we anticipated, and brought us the cooler weather," he said. "Now there is hope again that we can reverse the trend and moderate the fire situation this year."
Reviewing 121 years of record keeping for average temperature and precipitation showed that New Mexico experienced its fifth wettest and fifth warmest year statewide on average, he said. At 136 percent average of normal precipitation statewide, last year was the wettest since 1986, Bird said.
"There has been kind of a dichotomy (the past year) between eastern and western New Mexico, where there has been more precipitation east and less west," he said. "But short term through winter and spring, you can see a strong trend toward dryer weather. This area was much above normal for the last six months, but when you look just at March, it puts you much below normal, as was much of the state record dry last month."