Recap: Grading Our 2007-08 Winter Outlook

Passing, but not-so-perfect marks

Now that winter is officially done, it is time to grade our annual winter outlook. While we did have some successes, overall our outlook failed to capture the degree of warmth and lack of snow in what ended up as our warmest and least snowy winter since 2001-2002. Read on for a complete grading of the outlook.

OUR PREDICTED TEMPERATURES

December: Normal to +1°, Actual: +2.3°
January: Normal to +1°, Actual: +5.1°
February: +1° to +2°, Actual: +2.9°
March: -1° to -2°, Actual: +2.5°

December-March: Normal to +1°, Actual: +3.2°

What we did well:

  • We correctly predicted which side of normal temperatures would be for 3 of the 4 months (we missed March).
  • We correctly predicted that overall temperatures (December-March) would be above normal.

What we missed:

  • Our predicted coldest and warmest months did not come to fruition.
  • Overall temperatures finished well above normal versus our forecast of slightly above normal.
Temperature Grade: C+

OUR PREDICTED SNOWFALL

DCA: 12", Actual: 4.9"
IAD: 18", Actual: 6.5"
BWI: 18", Actual: 8.5"

What we did well:

  • We correctly predicted that all three airports would record below-normal snowfall.

What we missed:

  • Snowfall was well below normal versus our prediction of slightly below normal.

Snowfall Grade: C

WHAT WENT WRONG?

While many factors go into determining winter temperatures and snowfall, two in particular stand out as influences for this past season:

  • The La Niña event was stronger than we thought. This led to a persistent area of high pressure off the southeast U.S. coast that pumped warmer-than-normal air into our region and kept the prevailing storm track well to our west. Consequently, most storms were were in the form of rain for the D.C. area, and when it was cold enough to snow, it was usually dry.
  • The North Atlantic Oscillation (NAO) was mostly positive. Typically, when this index is positive, cold air masses have trouble penetrating our region for extended periods, and storm systems track to our west, leaving us warm and rainy.

Overall 2007-08 Outlook Grade: C/C+

By Matt Ross |  April 2, 2008; 11:15 AM ET Recaps
Previous: Forecast: Pleasant Weather Pays Short Visit | Next: CommuteCast: Clear Skies, Calming Winds

Comments

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Hi. A question less for posting, but just so I understand what I am missing.
Granted, I had to travel a good deal this winter, but it seemed to me that when in DC, temperatures were largely in/around the 40's, which I am to understand the norm. Sure, there were a couple warm spikes (extreme even), but those one or two days appeared to me regularly beaten back by yet another cold front. Is this a poor characterization of last winter? If not, then how does your tally account for what I thought were a predominant # of days with average seasonal temperatures? Thanks! Rich

Posted by: Rich Kraemer | April 2, 2008 11:48 AM

Rich....You characterization is correct....cold air was usually close by and often made it in here, if just briefly....We just didnt get enough anomalous cold to offset those days in the 50s, 60s, 70s....of which we had plenty..

Posted by: Matt Ross, Capital Weather Gang | April 2, 2008 12:02 PM

Bravo. I wish all the local forecasters would grade themselves on how good their predictions were.

Posted by: Mark1 | April 2, 2008 01:15 PM

One measure of how warm the season was is that there were no days when the high temperature was below freezing (31 or less) at DCA, according to WeatherUnderground's tables. Also, the low temp for November was 30, for December was 23, for January was 18, and for February was 16. Isn't it unusual to have a winter without any seriously cold weather, and what might the impact be on flowers, bugs, etc?

Posted by: Dick | April 2, 2008 02:48 PM

It was an overall pretty good winter forecast, I'd say. Wanted to echo the sentiment that this is one outlet where I see forcasters do an honest assessment at the end, good bad or indifferent.

Congrats again!

Posted by: Curtis | April 2, 2008 02:50 PM

Hey guys. Thanks for the review. I was wondering when it was going to come out.

I think you are grading yourselves a bit harshly, though. Your prediction post basically called for a rather tame winter, and that's what we got. Yeah, you were a little low on the snow totals, but that's only a couple events sliding by a little too much to the west. Maybe I practice too much grade inflation, but I'd easily put you above the 80% mark.

BTW, was there a spring forecast?

Oh, one other thing. I don't mean to upset the snow lovers, but from an economic sense, I loved this winter. My HOA saved a ton of money because we didn't have to pay for the plows to come out and remove the snow. After having to raise dues last year because of some other expenses, we really didn't need to come back and do it again this year because of 50 feet of snow. My wallet definitely thanks the weather gods for keeping us in the warm sector of all of those lows this winter.

Posted by: doug | April 2, 2008 02:55 PM

I was also grateful for the warm winter because it had a minimal impact on my warm climate shrubs, such as Italian cypress, osmanthus and loropetalum. I didn't have a lot of leaf burn as opposed to the winter of 2006-2007 when everything experienced leaf burn or simply lost its leaves entirely. This winter was more typical of those in North or South Carolina than the Washington, DC area. Cold spells were short-lived as was snow. Also typical of North Carolina, two of the more significant events were ice storms in February.

Posted by: Steve Wasko | April 2, 2008 03:21 PM

The Dec-Jan-Feb average of 40.9° was in the warmest 10% of winters (tied for 13th out of 138 years); all 3 months averaged 40 or higher.

Posted by: Steve, Capital Weather Gang | April 2, 2008 04:11 PM

Re earlier N.C. comment:
The winter mean would be closer to the long-term average for Raleigh (41.9°) than Richmond (38.8°).

Posted by: Steve, Capital Weather Gang | April 2, 2008 04:30 PM

While very dry, this winter was not the high-temperature disaster its predecessor was. No one seems to remember that we had NO WINTER from Dec. 1, 2006 to Jan. 20, 2007, just an extended autumn.

Posted by: El Bombo | April 2, 2008 04:40 PM

I would grade you all a "B". I thought your forecasts were pretty close.

Posted by: A | April 2, 2008 09:59 PM

This winter was also unusual in that there were several severe thunderstorm events in the area...probably because we were in the warm sector of several low-pressure systems that passed off to our north and west, instead of the more normal situation of us being on the cold side of the storm with winter precipitation, when the storms pass of to our south and move up the coast.

Posted by: Mike | April 3, 2008 01:06 PM

I agree you're being too hard on yourself. Nature is rarely as predictable as we would like it to be...Just ask Maurice and Katia Krafft. Perhaps wishful thinking played a part. You definitely get an A for effort and contribution to the greater good.

Posted by: Ann in Cincy | April 3, 2008 03:16 PM

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