Spring has Sprung: An Analysis of CPC’s Spring 2019 Outlook (Photo Credits: NOAA’s Climate Prediction Center, Fred Dunn)
NOAA's CPC outlook for April-May-June (updated March 21 2019) ; MLK Memorial in Washington D.C. surrounded by cherry blossoms in March 2018
This morning, the Climate Prediction Center (CPC) released its three-month outlook for spring temperatures and precipitation. An official El Niño declaration was made about a month ago, with positive temperature anomalies reigning in the central Pacific.
The CPC makes 6-10 day outlooks, 8-14 day, monthly, and seasonal outlooks across the United States. For example, the three month spring outlook (April-May-June) gives the probability of of precipitation occurrence on the three upcoming months of the forecast model run. Probability of precipitation will be in one of 3 possible categories: below (B), median (N), or above (A). Categories are defined by separating the 30 years of the most recent climatology period 1981-2010 into the 10 driest years, the middle 10 years, and the wettest 10 years on any given 5-day period. The probability of any category being selected at random is ⅓. The colored shading on the map indicates the degree of confidence. The darker the shading, the greater level of confidence.
For New Mexico, in particular, the Madden-Julian Oscillation, or MJO, played a bigger role in active winter weather systems. But, what does that mean for spring across northern and central New Mexico? Wetter than normal conditions are more likely during El Niño events in the Southwest, especially during the cool season months of winter and spring, in which there is an eastward extension of deep tropical convection. While odds generally favor a wetter winter during El Niño, an analysis of individual stations reveals precipitation to be highly variable from event to event. Temperatures are more of a mixed bag, based on current dynamical and statistical output and historical trends (i.e. whether an earlier spring snowmelt will affect higher elevation temperatures). MJO, on the other hand, is forecast to remain active through the end of the month, where mid-latitudinal teleconnections become weaker during the spring months. While an El Niño event will tilt the odds for a wet winter and spring in New Mexico, it does not guarantee above average precipitation.
Following a round of chilly temperatures and a polar vortex, it looks like the groundhog may have forecasted spring at an opportune time!
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©2019 Meteorologist Sharon Sullivan