Tim’s 2013 – 2014 DC Winter Forecast

Please Click HERE for Tim’s 2014 – 2015 DC, Baltimore, Philadelphia, New York City & Boston Winter Forecast

anomnight.10.21.2013

Current Global Sea Surface Temperatures (SSTs)

 

We are rapidly approaching winter and many want to know how much snow will fall across the D.C. Area.  I have seen predictions ranging from a “brutally cold winter” (Old Farmer’s Almanac) to a mild winter with very little snow. 

  • Last year in the D.C. Region, snowfall varied greatly across short distances. Fredericksburg, Warrenton, Manassas and Leesburg received between 10 and 20 inches of snow with the Urban Heat Island of DC receiving less than 4″.  March was incredibly snowy across the southwestern suburbs/exurbs with nearly 11″ that month alone.  I remember friends calling me in D.C. with wet snow falling (but not sticking) and yet I was shoveling 8″ of snow off my driveway.  Let’s briefly take a look at conditions across the Equatorial Pacific to see the factors that can shed light on this year’s winter forecast.

 

  • The Oceans play a huge role in our climate.  Two factors have not changed since last winter.  First, current Sea Surface Temperature (SSTs) anomalies depict neutral conditions (“La Nada”) continuing during the upcoming winter.  Second, the PDO (Pacific Decadal Oscillation) remains negative (in its cold phase).

 

  • Bottom Line: Just like last winter, I don’t expect an active southern branch of the jet stream to be a major playerI expect either a split jet stream or a strong northern branch to be dominant during the upcoming winter season. (The strong southern branch during the El Nino winter of 2009 – 2010 produced the moisture needed for very heavy snows across the D.C. Area.

Let’s look at specifics:

Latest forecast models show a high probability of neutral conditions (“La Nada”) continuing through March of 2014.

ENSO_forecast

Winter 2013 – 2014 Analogs

In choosing my analog package for this upcoming winter forecast (December through February) I looked for the following:

  • Neutral ENSO (La Nada) winters
  • Followed by a wet spring and summer
  • Occurring after back-to-back La Nina Winters

The analog packages of 1961, 1962, and 2008 matched up fairly well. It is impossible to get a winter forecast 100% right every single year, so it really comes down to probabilities.   A winter forecast is only as accurate as the analogs (historical years) that you choose. Last year, my winter forecast was accurate for most locations in the Virginia piedmont (Warrenton, Leesburg, Fredericksburg, Manassas, etc.) and northwestern Maryland (Frederick) while D.C. was a bust (thanks to the low level easterly flow off the warm Chesapeake that destroyed the temperature profile during the mid-march snow storm).

 Temperatures and Precipitation:

 

2013_2014_temp_analogs

Temperatures across the Mid-Atlantic and New England should remain below to slightly below normal.   Temperatures in the Midwest will be well below normal with frequent arctic outbreaks.

2013_2014_precip_analogs

Precipitation across the Mid-Atlantic and New England (Northeast) should be near normal.

Winter 2013-2014 Highlights:

  • New York, Philly, Baltimore and Washington (pink zone) will be situated in the battle zone between snow and ice this winter as the southeastern ridge and strong northern branch of the jet stream may play a role in keeping the average storm track off to our north and west this winterIf this track verifies, mixed precipitation events as well as several snow events can be expected with near normal to below normal snowfall.

 

  • I expect average snowfall across southern New England (Boston, Hartford, Providence) with above average snowfall in northern New England and the Midwest.
2013_14_Trends

Storm track will vary with the trough axis shifting back and forth between the Ohio Valley and East Coast. Heaviest snows will remain across Northern New England, the Ohio Valley and Lake Effect Snow Belt.

Based on the analog years I chose, how much snow could fall across the Washington D.C. Metropolitan Area during the upcoming winter season?

Winter_2013_14_prediction

Tim’s total seasonal snowfall accumulation forecast across the 3 major airports during the Winter of 2013-14.

 

Average Snowfall in the Washington Region:

washington_dc_region_average_snowfall_dcstorms-com

Average Snowfall in the Washington Metropolitan Area:

washington_metro_average_seasonal_snowfall_dcstorms-com

5 thoughts on “Tim’s 2013 – 2014 DC Winter Forecast

  1. David

    This was really put together well, Tim. It showed courage to make a decision. It was educational without too much technical pieces. The graphics and maps are always awesome.

    On Wed, Oct 23, 2013 at 8:42 PM, DCstorms.com

    Like

  2. Jason

    I enjoyed learning more about the active southern branch that brought us the 09-10 blizzards. Hope we see that again in the coming years 🙂

    Like

  3. Andy

    I am new to your blog and didn’t see your winter forecast until just now, but you did a remarkable job. A detailed forecast like that is never going to be perfect, but you got many of the hghlights down remarkably welll, mainly the unusual cold and snow around the Great Lakes. You also had the big snowfall gradient in the Northeast down very well, even if details were not perfect. Nice job!

    Like

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