November 15-16, 2018 Winter Storm Review: Snow Maps, Forecast Report Card

Storm Maps

The Finger Lakes was besieged by one of the earliest major snow storms in 20 years with widespread amounts of 10-12 inches.

The map at the top of this blog post is an estimate how the snow fell across the region.

An axis of heavy snow sticks out from Steuben County northeast towards Oswego County. Just outside of this heaviest axis, very significant amounts of snow still fell.

This axis of heavy snow was expected but ended up further northwest. The distribution of double-digit snow totals was also more widespread across the region than anticipated.

This map was created with reports published by the National Weather Service. I then applied an inverse-distance weighting algorithm to the data to extrapolate it.

I chose parameters that applied quite a bit of smoothing to the data. While this likely smoothed out some high and low amounts, the goal of the map is not 100% accuracy, but to be able to view patterns for studying and forecast verification.

I also took the same map and reclassified it to match the color scheme of the snow maps I published before the event. The forecast is shown on the left, the actual amounts on the right.

While my forecast was in the ballpark for how much snow would fall at a maximum, a much larger area saw those high snow totals than was expected.

Sleet did mix in for a time Friday evening, especially over the eastern Finger Lakes. This may have reduced snow totals very slightly.

This storm was uncommon in how widespread it was so early in the season. Ithaca, for example, has not seen over 8 inches in a single day this early in the season since 1997.

However, heavy snow events do happen on occasion in November and have happened even earlier in years past. Nonetheless, this storm will be remembered for years to come.

Forecast Report Card

Now I would like to take a look at my own forecasts and services more critically and grade myself on how I did with the storm.

Good Points

• Among the first to predict snow totals approaching a foot.
• Forecast timing of the storm was basically perfect.
• Maximum amounts matched expected upper bounds (13-14 inches).
• Correct thinking in areas of sleet and its impact
• Unparalleled coverage and interaction with the public before and during the storm.
• Consistency in forecast: only one snow map issued.

Weak Points

• Underestimated area of double-digit snow totals.
• Northwestern Finger Lakes (Canadaigua and surrounding areas) saw nearly double the amount of snow as predicted.

Total Misses

• None

Overall Grade: A-

Summary: No forecast is perfect, but some do come close. I would have preferred to be closer to that mark over a wider area. For the Southern Tier and eastern Finger Lakes, the forecast was very close to being perfect. To the north and west, I underestimated by too much to be satisfied. I give myself bonus points for being 12-24 hours ahead of the local competition with calls for a foot of snow, having just one single forecast to communicate instead of bouncing around, and for blowing the competition out of the water with my coverage and interaction with the public. In the end, my followers were by far the most informed, had the best idea what to expect, and had their trust in my forecasts and processes rewarded.

Lessons Learned: The Euro is KING among the models. This is nothing new to me, but time and time again, the Euro captures ideas well ahead of other weather models that other services stubbornly hang on to. Every time I start to wonder if this will be the storm where the Euro falls…it once again rises to the top.

A second lesson that was reinforced to me was to never underestimate the sleet. Time and again I convince myself in these storms that the sleet will not make it in, and yet it always does. The impacts were small this time, but I will add this storm to a long list of others that ended up having sleet.

Customer Feedback

Analyzing my own work is great, but it is also important to see what others are saying:

• Drew just really digs deep into what’s going on and uses his long experience combined with hard work studying the models. Because of this amazing effort, he gives realistic forecasts that match what actually happens! It’s so nice to have a weather report that’s actually reliable and honest. Drew doesn’t hype things up to get viewers he tells the truth to keep us in the know. • Marie-Ann (Facebook)
• Accurate, timely forecasts that are specific to the Finger Lakes region. Rochester and Syracuse forecasts aren’t always accurate for our FL microclimates, but Finger Lakes weather tells us exactly what to expect in our own communities. • Marcia (Facebook)
• Drew treats weather like what it is, weather, instead of like a tabloid news story. It’s convenient to have a weather report I can actually trust instead of trying to figure out how dramatic other forecasts are being. Drew is up front about his confidence level in the forecast, which increases mine. He updates frequently, too. • Shannon (Facebook)
• Drew, thanks to your no-hype, accurate forecasting, we got our team home SAFELY before dark (and my hubs too). Immediately following, there were reports of evening commuters stuck all over the hills around Newfield. Thank you for the attention you pay to dissecting these storms and therefore keeping people safe! #bestweatherguybyamile • Jodi (Facebook)
• The best source for reliable #FLX #weather is surely @FLX_Weather ! Thanks for keeping us up to date Drew. It makes it easier to stay safe and make smart decision. • Mark (Twitter)