Warmer temperatures have invaded the East overall following a very chilly start to the new year, but significant changes are coming. The WeatherOptics team is carefully examining all of the latest model guidance and bringing to you our outlook for February in this article.
The current overall pattern across the East as of late and through the rest of January is a ridge of high pressure over the East and a trough of low pressure over the West. With a ridge, temperatures are typically warmer than average whereas a trough delivers cooler than normal temperatures. By the second week of February, however, the pattern is likely going to flip-flop with a trough over the Eastern U.S., as shown below. This trough will lead to not only colder temperatures but likely a continuation of the active weather. That mix of cold and wet weather is the perfect recipe for powerful snowstorms,
There are several different factors that will contribute to this pattern change. One of which is the change in the MJO phase. MJO, or Madden Julian Oscillation, is a major fluctuation of tropical weather tracked on a weekly basis and, in simplistic terms, is an area of enhanced rainfall and convection (thunderstorms). These areas of enhanced convections are known as pulses, revolving around our planet, recurring every 30 to 60 days. Believe it or not, what happens near the equator with these pulses affects the weather across the globe. Currently, the MJO is in the phase 4, but is forecast to transition to phases 5, 6, and eventually 7 by early-February. By this time period, the MJO will be in a favorable phase for a cold and potentially stormy or snowy Eastern U.S.. It will also be at an increased amplitude, further influencing the pattern.
Another factor we look at when forecasting the long-range pattern is the different oscillations, excluding the MJO. There is one particular pattern we’re going to focus on: the Arctic Oscillation (AO). The AO is forecast to dive into a negative phase, which leads to a more active weather pattern due to a meridional flow. To keep it more general, it leads a curvy jet stream and more weather extremes and contrasts in the Northern Hemisphere. The forecast AO from the European model indicates an upcoming change, going from a positive to a negative phase.
Lastly, the new European weeklies came out on Monday, and they continue to show a trend of cold and snow for the East and Northern Tier. The forecast precipitation anomaly is projected to be above average for the East overall, especially in the Northern Tier, Gulf Coast, and the Northeast coast. This often foreshadows the storm track. Based on this data, we are forecasting an active storm track with both the jet stream and the subtropical jet stream. Expect several clippers moving through the north, with storms coming across the Gulf Coast states. There is also the indication for an active storm track just off the Northeast coast, which may mean more Nor’Easters are ahead. With cold air in place and an active weather pattern, it definitely looks favorable for significant Northeast snowstorms in February and early March.
The European weeklies also forecast temperature, and with no surprise based on what we’ve been focusing on: the East is likely going to turn cold with below average temperatures overall. This winter has been harsh already, and Mother Nature doesn’t look to settle down with her cold spells any time soon.