March sure has been a wild month! Indianapolis is running close to 4° below average on the month with around one foot of snow. The highlight was obviously the 10.2″ of snow that fell last Saturday.
Largely this was driven by the return of blocking- something that has been missing most of this winter and, for that matter, the past couple of winters. Note the prolonged, sustained negative NAO. As we’ve written in the past, the NAO, or North Atlantic Oscillation, is the “king” this time of year. In late winter and spring, negative NAO phases will result in cold periods, even in the face of potentially warmer signals from other, less dominant, teleconnections.
As we look ahead, we don’t really see any significant changes with the forecast NAO into mid-April.
To no surprise, the pattern remains colder than average over the next couple of weeks, overall.
European ensemble predicts well below normal temperatures in the Day 5-10 period, courtesy of Weathermodels.com.
European ensemble predicts well below normal temperatures in the Day 10-15 period, courtesy of Weathermodels.com.
With all of the cold around, it should also be no surprise that at least the threat of additional accumulating snow is on the table. In fact, an item of “interest” will eject out of the Rocky Mountain region and into the Plains and eastern half of the country in the 8-10 day period. It’s far too early for specifics, but at least the potential of accumulating snow is present next weekend across the Ohio Valley.
It should be no surprise that the GEFS 5-day temperature anomaly shows widespread below normal air centered on March 22nd.
This doesn’t mean brief surges of warmth, originating in the southern Plains, can’t shoot into the Ohio Valley for a couple of days. Perhaps we’ll “luck out” and enjoy a briefly milder time for St. Patrick’s Day. This does, however, mean that overall we have a long, long way to go before “stick and hold” spring can arrive, locally, and the balance of the upcoming 2-3 weeks looks colder than average.