Remembering the October Surprise Storm

We extend our sincere condolences to those who lost loved ones, and to those Western New York residents who were impacted by this devastating storm.

The metropolitan area of Buffalo, New York is no stranger to a foot or more of lake effect snowfall from mid-November to January, however when these snows occur early in the season, like October for example, it does pack a punch.

On October 12th and 13th, 2006, a localized, intense, and early season lake effect snowstorm hit the city of Buffalo and its surrounding areas. Upwards of two feet of heavy, wet snow fell from a narrow lake effect band that developed over the warm 62 degree waters of Lake Erie. While the band covered a small area of 25 miles wide and 40 miles long, the location of the band centered over the most populated neighborhoods of Western New York, with nearly one million people directly impacted by the storm.

Why was this storm termed a "surprise"? Let's take a more in depth look to find out.

Up to a week in advance model guidance packages began to point towards an anomalously strong low pressure system to set up across the Great Lakes. Fast forward a week, the low pressure system set up and pushed in much cooler air across Lake Erie, which caused lake effect processes to set up. Here's how the forecast evolved over time:

As we see from the morning conditions some form of lake effect precipitation was inevitable. Which leads us to what kind of precipitation would fall, would it be snow, a mix or rain? Forecasters at the time were wary that even though the cold air aloft would support snow, the warm lake temperatures would keep the temperatures near the surface too warm to support snow, and if so, would there be significant snowfall accumulations?

Climatologically speaking at the time, Buffalo had never received more than 4 inches of snowfall this early in the season, but as the morning forecast update said "we can't forecast based on that."

By Thursday morning, lake effect rain was falling across metro Buffalo and its immediate suburbs.

Midday, the cold air deepened overhead of the warm lake waters, which begun the transition of widespread lake effect rain showers to have a mix of graupel.

Winter Storm Warning was issued and highlighted:

• 1 to 3 inches of wet snow with isolated heavier amounts of up to 6 or more inches
• plenty of doubt regarding snowfall accumulations due to the warm ground and lake temperatures
• BUT, the heaviest activity was expected during the overnight hours, which will minimize melting and allowing for more snow to accumulate
• Major Expected Impact: Trees still in full foliage, so even a few inches of wet snow may cause tree damage and possible power outages

By 2 PM precipitation changed over to snow at the National Weather Service office and according to a former forecaster,

By 3 PM roads were graupel covered.

Snow would keep falling across metro Buffalo and its surrounding areas into the evening. By early evening a few storm reports rolled in with a couple of inches of snow accumulating, along with downed limbs and trees, as well as thundersnow. In fact, the switch over to snow, thundersnow became quite frequent for almost a 12 hour period, unofficially marking the longest period of of frequent observed thundersnow.

Click on the pinpoints on the map to see the actual reports.

Heavy wet snow continued to wreak havoc throughout the evening hours. It was during the first half of the event where the snowfall contained an unusually high amount of water, where snow to water ratios measured 6:1 at the NWS office. Additionally, it was during these early hours where forecasters who worked this evening remarked, "[it] sounded like 'rifle shots' as large tree limbs snapped."

Another forecaster remarked,

It was such a surreal night.

As the colder air continued to filter in across the area overnight, snowfall rates increasd up towards four inches per hour as well as snow to water ratios climbing towards 12:1.

Sometime in the morning of Friday, October 13th, the snow band shifted north into Niagara county before it would transition back to rain and taper off. Some final snowfall reports can be found below in the map.

As you can imagine, this much snowfall for early October is quite unusual for the Western New York area, especially when the snowfall fell on fully foliated trees. The bulk of the damage was tree loss. Initially, the first couple of inches took out tree limbs, then as the heavy wet snow continued whole trees were soon to follow. According to a former NWS forecaster,

The first 4 inches did the real damage.

The fallen trees and limbs brought down power lines, impacting homes and businesses across the north side of Buffalo even before nightfall. One meteorologist recalled,

Power outages began around 5 PM.

However the damage and destruction didn't stop here, the water laden snow also brought travel to a halt, causing the Buffalo-Niagara International Airport to close down due to snow clogged runways and the facility lost power. Also, a 105 mile stretch of the NYS Thruway closed between Rochester and Dunkirk, confining customers to their cars for 12 to 18 hours. While the impacts to both air and roadway travel were cleared relatively quickly (around 24 to 36 hours), the damage of trees and power outages would burden the area for an additional couple of weeks. It took approximately two weeks for all four-hundred-thousand customers to regain power after the storm.

Click around on the map to see pictures of the snow, damage and impacts of the event.

Outside of shear damage caused by the trees, no major structural problems impacted homes. However, mild temperatures the following day would rapidly cause the snow to melt. Local streams were able to handle the extra water, the combination of the runoff and the lack of power to run sump pumps caused basements to flood.

Unfortunately, Buffalonians would lose a few lives during the days after the storm due to improper ventilation from heaters and generators producing carbon monoxide fumes. This prompted the National Weather Service office to issue a Public Information Statement, reminding folks to take proper precautions during clean up.

As for the NWS Buffalo staff, most of us lost power during the storm and endured the compounded problems within our own basements. In fact, a few of our forecasters distinctly remember the help from our colleagues from the NWS Binghamton office who sent their own personal generators west to help pump out basements.

Some may say that to this day, the October 12-13, 2006 storm was the worst October storm that Buffalo had ever seen, and quite possibly the most destructive of all time. The 22.6 inches measured at the Buffalo-Niagara International Airport continues to mark the highest snowfall for the month of October and the damage inflicted by the heavy wet snow can still be seen in the landscape across some neighborhoods.

With this in mind, the afternoon forecast discussion from Thursday October 12th stated:

Dramatic and possibly historic event underway for metro Buffalo.

A completely correct statement, which acts as evidence that the forecasters understood the conditions that would provide for a significant event. Additionally, the storm was mentioned in the forecast discussion up to a week in advance, however the real surprise came from the impacts a few inches of wet snow created. Original thinking was the first six inches would cause the power outages, but in reality the first few inches caused the power outages to occur in the early evening and therefore creating the surprise.

So why did this thinking occur?

Well, it wouldn't be accurate to say that an early season snowfall hadn't occurred in Buffalo, when in reality it had occurred three times prior (1895, 1906 and 1930) to the 2006 event. However, the oldest forecaster in the office at the time would have to be in their mid to late 80s to have remembered the early October snow storm in 1930. Therefore, it was understandable that forecasters were questioning the effects of the cold air over such a warm lake.