With February about to finish up as the warmest on record and the winter competing for the top spot, too, we turn our attention to the first month of meteorological spring to see whether anything different is looming.
This will further accelerate the early onset of spring, and we expect trees and flowers will hit peak bloom near their earliest points in recorded history. Our detailed cherry blossom outlook will be released Tuesday.
Although we expect the month to be mild overall, there are likely to be some brief cold shots, so don’t put away the winter coats just yet.
Our outlook specifics follow:
Temperatures: We favor temperatures to average four to six degrees warmer than normal (normal is 46.8 degrees). For reference, last March (2016) was nearly eight degrees warmer than normal.
Rain: We think rainfall will end up 0.5 to 1.5 inches below normal (normal is 3.48 inches)
Snow: No measurable snow is more likely than not. Maybe we’ll see a few flurries. Normal March snowfall is 1.8 inches.
If our temperature outlook holds true, March 2017 will rank among the top 10 warmest. Forty percent of the warmest Marches on record have occurred since 2000:
Forecast rationale
Persistence wins. Our so-called winter has been a broken record of record-breaking warmth. So why should March be any different? The year-to-date temperature difference from normal tells the story:
Even when we witness some periods of colder weather, the warmer periods are stronger and longer. For example, just look at the forecast for the first day of March (Wednesday) when temperatures may surge into the 70s yet again:
Limited cold air connection. The very warm end to winter over the Lower 48 states has decimated snow cover well to our north and west, which means that any cold air masses that come our way tend to moderate (weaken) faster than they would ordinarily. This means the cold periods lack the bite they would have otherwise.
A powerful Pacific jet stream. A fast-moving jet stream originating from the Pacific Ocean still dominates the pattern, which floods the West with rains and mountain snows, while undercutting the ability for Canadian cold air masses to make much progress southward. Computer models are a bit of a chaotic mess right now, but they continue to suggest the strong Pacific jet stream persists in the month ahead.
Dry soils. The dry weather pattern also contributes to amplifying our warmer periods, allowing daytime high temperatures to get even higher thanks to the lack of soil moisture. There is a chance that this dry narrative switches gears later this spring thanks to the development of a new El Niño event in the Tropical Pacific. It has the potential to ease the drought by late spring or into the summer.
Models. The National Weather Service’s long-range weather model continues to show a warm month ahead, although it’s a moving target on precipitation.
Its average forecast over the past five days advertises a warm and wet scenario. However, keep in mind it was way too wet for February and seems to have developed a wet bias in recent months. If it is correct with the wet forecast, it may be more focused toward the second half of March when the developing El Niño event may have more time to offer some influence. We’ll cross our fingers, but confidence is much higher on the temperature forecast than the precipitation side.
National Weather Service. They don’t offer much guidance here. Their outlook is indecisive on March conditions, indicating “equal chances” of below normal, normal, and above normal temperatures and precipitation. We understand the ambivalence on the precipitation forecast, but to us a milder than normal March is a pretty safe bet.
