While a snowy February holds basically no predictive power over how much snow March and April might produce, there’s a different metric that might just indicate that Colorado could be in for a snowy spring.
The Pacific North American Oscillation, known simply as the PNA, . And this metric may indicate a more favorable environment for a snowy spring across Colorado.
Colorado Springs-based television meteorologist Brian Bledsoe recently noted that the PNA is in a deeply negative phase, which is associated with a stormier spring in Colorado. The is for the PNA to remain negative through at least the middle of March.
A key teleconnection in producing big storm potential for March, is the Pacific North American Oscillation. When in a negative phase, storminess is favored over the Western US. No guarantees, but I'm interested in March for this reason…
— Brian Bledsoe 🐊 (@BrianBledsoe)
According to the Climate Prediction Center, tends to equate to above-average precipitation for Colorado and much of the central United States. That extra moisture can also carry over later in the year and as well.
In general, this is due to a lengthy domino effect of global weather that typically results in a period of below-average air pressure across the western United States. Lower air pressure is correlated with cooler and wetter weather, and during the stormy spring, that can create a more favorable environment for big snowstorms in Colorado.
But this pattern is also typically tied into the El Niño and La Niña (ENSO) cycles of Pacific Ocean water temperatures. A negative phase of the PNA is often associated with La Niña, or cooler-than-average sea surface temperatures in the central Pacific. , perhaps a slight nudge that the negative PNA might not entirely have its usual predictive power.
It’s also worth noting that the PNA is a highly variable and complicated metric used in long-term forecast assessments, an emerging and still preliminary field within meteorology. You could think of the PNA link like a game of poker: if you draw a king, you probably stand a chance at a decent hand. But you, your other card, the cards on the table and other players will collectively and ultimately decide whether you win or lose the hand.
Coupled with the active streak of winter storms in Colorado and a generally cooler winter, though, and the negative phase of PNA could be an indicator that plenty of spring snow could be just around the corner.
