With lots of wintry weather in the coming days, we can say that March 2015 is coming in like a lion indeed; but how will the whole month shape up for our area?

Many of us are probably anxiously awaiting spring after the coldest February since 1979, while other snow fans may be looking for those final flakes to potentially push Washington, D.C. to an above normal snow season (through February, D.C. snow has 13.5 inches versus a seasonal normal of 15.4 inches). Currently, odds seem in favor of another colder-than-normal month, but this time with more precipitation.

Fortunately, March is a month that can satisfy all preferences. Last year saw the coldest March of the 2000s with the most snow (and a snow event as late as March 25th!), but we still managed to hit 60F or higher eleven times with three of them at or above 70F.

[U.S. runs hot and cold in record-shattering February]

Here are the 30-year climatology benchmarks for Washington National airport for March for reference, along with our projections for the coming month:

Normal Temperature: 46.8F. Projection: 41-45F

Normal Precipitation: 3.48 inches. Projection: 3.75 inches or more

Normal Snowfall: 1.3 inches. Projection: At or above 2 inches

Rationale

Let’s discuss the primary factors utilized for the March outlook.

Head start: The first week to ten days are favored by the dynamical computer model guidance to be colder and wetter than normal with medium to high confidence. This supplies about one-third of the month’s result and is a head start in this direction. In fact, we have a chance to exceed March’s normal snowfall by Wednesday night or Thursday morning based on some model guidance. Month-to-date temperature anomalies should be about three to five degrees below normal by March 10, with precipitation near to above normal.

Extended range guidance: Longer-range modeling suggests that the cold pattern in the first third of March for the Eastern U.S. may break down and give way to a warmer regime for the middle third of the month before shifting back colder again for the final third. Confidence is typically low on extended range weekly guidance (CFS model and European model weekly outlooks), but they have offered some degree of consistency in the past week. The cold start, warm middle, and cold March scenario is also very similar to last year.

[There is light at the end of this winter’s cold, dark tunnel]

Similarities to 2014: This is the classic “persistence” argument. Just like last winter, the big story this year has been huge blobs of high pressure over Alaska. These massive features have wrinkled the polar jet stream and sent big blasts of arctic air pouring southward into the U.S. This pattern tends to persist for about two to three weeks, breaks down for about a week or so, then rebuilds again. The extended range guidance is repeating this pattern as described above, which matches the behavior seen frequently this winter and last.

Ocean and atmosphere: We have a marginal weak El Niño pattern in the Tropical Pacific along with a positive Pacific Decadal Oscillation (PDO). The weak El Niño should provide more wetter than drier months to the South and East Coast (last month was an exception), while the PDO pattern should continue to support big high pressure ridging in the North Pacific in and around Alaska. Earlier this winter, we saw stronger tropical forcing (Madden-Julian Oscillation or MJO) that prevented the pattern from being as cold (mainly December and middle to late January). That forcing looks quite a bit weaker now and should not play as much of a role, allowing the winter “base state” to prevail.

[In like a lion: Icy photos and totals from March 1 storm]

Other views

Here are the latest forecasts from the National Weather Service and my company, the Commodity Weather Group. Notice there is at least general consensus for the Eastern U.S. Please remember that long-range forecasting is a very difficult challenge given the variability and chaos inherent in atmospheric patterns, but I find when there is consistency and consensus, you tend to achieve better accuracy.



National Weather Service March temperature outlook

Commodity Weather Group March temperature outlook



National Weather Service March precipitation outlook