February and the meteorological winter (spaning December through February) have just come to a close, but why do I feel like we are transitioning from autumn to spring right now? This has certainly been a winter in name only as we continue to draw sharp contrasts against the previous two colder-than-normal winters. So let’s look at how we stacked up in the final tallies...
The warm and dry themes of January carried right on into February, which allowed 2012 to record the first top-ten warm February of the 2000s - fourth warmest to be exact. Our average monthly temperature of 44.3 degrees was 5.3 degrees above average and a remarkable 19.7 degrees warmer than the all-time coldest February of 1934 (average temperature of 24.6 degrees). On the flip side, it was 2.6F colder than the all-time warmest February in 1976 (average temperature of 46.9 degrees).
The extra day for Leap Year gave precipitation as boost as we saw the most rainfall of any day with 1.44” at Reagan National. This reduced our deficit for the month to a mere -0.29” and our annual deficit down to -0.91”. Snowfall was a paltry 0.3” for the month, 4.5” below normal.
How did we spend most of our days and nights in February? Well, weather-wise, I mean. Our warmest day was actually way back on February 1, fittingly a day before Groundhog Day, when we soared to a high of 72. Our coldest day was back at mid-month on February 12th when we had a chilly low of 23F and only scraped above freezing at 33 for the high. 18 out of 29 days reached 50 or higher in the month. Only 5 or 29 days had lows at or below freezing.
We didn’t break that many records in February. All the area airports reported record high minima on Groundhog Day (February 2), and Dulles hit a record high of 66 on February 1, breaking the prior 65 from 1993. The only other records were one-day rainfall records at Dulles and BWI yesterday (February 29).
A big story about what happened this February is how the strong Pacific jet stream drove strong warming (ridging) up across southern Canada, which effectively cut off our more typical cold air supply connection. You can see this by looking at upper level height anomalies here:
The close of February also closes our meteorological winter, December through February. How did this warm winter fare overall? This certainly reminded me of the 2001-02 winter around here when we couldn’t get cold weather nearly the entire time, and snowfall was in super short supply. Well, it turns out that this winter edges out the 01-02 winter by .1F to be the third warmest on record. It’s definitely the warmest modern-day meteorological record, but still an entire 1 degree behind 1890.
And as we all know, this winter has also been characterized by its dearth of snow. Sure enough, the meteorological winter also landed in the top ten least snowy seasons with only 2” (tying with 2008-09).
The warm pattern rages onward. The indications from nearly all sources right now favor a warmer-than-normal March, but one aspect that may change is the precipitation story. The increasingly active storm track and jet stream pattern could push the region back toward seasonal or surplus precipitation in March.
I have looked back at other big warm March periods, and it is not out of the question to see occasional days in the 70s and even a spike or two into the 80s (already!). Typically such big March warm spikes are characterized by low humidity (so no need to worry about AC yet) and short durations (usually just a day). And March is still volatile enough that we can’t rule out a stray snowflake in a brief cool-to-cold push.
Link: National Weather Service’s latest March outlook update (issued yesterday) .
For Further Information
The National Weather Service publishes nice monthly assessments usually within a week of the close of each month (should be available shortly):
You can click on your closest airport location here:
The National Weather Service also released a recap of meteorological winter.
Historical Washington, DC data provided by Speedwell Weather and NOAA. Also, check out Ian’s excellent rundown on February climatology .