Post-Mortem: October 29th Snowstorm

**Note:  The contents and thoughts of this and any other post by me are mine personally and do not necessarily reflect the views, position, or forecasts of AccuWeather.**

After a historic snowstorm for anytime of year, let alone October, let's take a look at how my forecast turned out.

Snowfall Map

Courtesy of AccuWeather

Please see post below for my map.

Overall I think my forecast was above average. Let's break down the good and the not-so-good.

Good

• Nailed the western and northern edge of accumulating snow
• Very good forecast of gradient over Vermont and New Hampshire
• Good forecast of jackpot in NE PA and N NJ
• Verified the tight gradient just north of NYC (2" in CPK)
• Verified the tight gradient just north of BOS
• Pretty good forecast of 6+"
• Nailed the accumulating snow in NYC

Not-So-Good

• Underestimated snow totals in Berkshires and southern NH where jackpot was (25-35" in some spots!)
• Slightly too north/south oriented with my snow area, should have been a bit more SW/NE
• Overdone in N central PA; heaviest bands ended up just south and then shifted east meaning precip was too light over this area and accumulation was tough
• Did not forecast mountain enhancement across WV and SW PA
• Too close to the coast with accumulating snow

What We Learned

• Snow CAN accumulate in New York City in October under perfect circumstances. Many respected meteorologists argued that climatology said no snow would occur. While this was a good argument, this storm was so anomalous, the moisture so plentiful, and the dynamics so ridiculous, that the possibility had to be accounted for and in the end, it happened.
• It can thundersnow in Harrisburg (http://www.youtube.com/watch?v=w2YuPz3q1rU) in October. The convective bands that developed over the region were quite something.
• If the snow rates had been less, the accumulations would have been much less due to the warm boundary layer in late October. One of the biggest things that I think was underestimated were the snowfall rates and how that would play a role on accumulations. If it snows hard enough, it WILL accumulate, and the opposite is true which is why there is a void of heavy snow in N central PA.
• The power outages and downed trees were as bad if not worse than advertised by the media. Some people believed that it was being hyped. In the end, it was awful as thousands remain without power.

In general, I think this storm was very well forecasted less than 2 days before the event. Outside of 2 days, poor model consensus led many forecasters to believe this storm would head out to sea. In retrospect, the weather pattern favored more of a progressive and out to sea solution. However, everything came together at the exact right time to prevent that scenario from occurring.

Finally, this discussion would not be complete without giving major props to the European Model which nailed this storm from 5 days out with multiple runs of the same solution. It was not without its flaws though as it shifted east about 3 days away from the storm, leading to a brief eastward model consensus. From that point on, the trend was west, back to the original Euro idea.

Looking forward to a great winter season!