Wednesday, January 26, 2011

Just how low did it go?

Original post appeared on on 1/26/11; posted by Drew Montreuil. This version is edited.

You certainly do not need a meteorologist to tell you that the cold was bone-chilling Monday morning. However, you might be interested to know how cold it actually got across Central New York.

Click the map for a bigger view!

I put together a map of reported low temperatures from around Central New York. Most of these low temperatures were reported to the National Weather Service through co-op spotters. Some of the other readings were recorded on personal weather stations that upload data onto The Weather Underground.

As you can see, the temperatures can vary greatly over a short distance depending on a number of factors, including elevation, proximity to water and urban vs rural settings. A great example of this is Groton's reported -8º. This temperature was taken at a high elevation somewhat near the Elementary School. On cold nights, the coldest air settles in the valleys. Therefore, I would not be surprised if someone sees the map and thinks: "But I saw the bank thermometer Monday morning say -15º!" Down in the valley, it probably did drop below -10º. If anyone does have a lower reading from downtown Groton, I would be very interested in it, so please leave a comment!

For comparison to previous years, we have to look at Syracuse, since climate data from the NWS is only available for Syracuse and Binghamton. You may be interested to know that the -13º was the lowest temperature in the past few years. The lowest temperatures for the past few years in Syracuse are as follows:

  • 2010: -9º
  • 2009: -2º
  • 2008: -4º
  • 2007: -9º

Data from before 2007 was not available on the National Weather Service's Climate site for Syracuse. I can, however, tell you that the -13º is no where near the record low for Syracuse since observations began at the airport in 1971. That record belongs to February 1979, when it was -26º.

Friday, January 21, 2011

Winter's Fury Unleashed

As posted by Drew Montreuil on, 1/21/11

Old Man Winter sure is angry these days, and we will not be escaping his wrath over the next week or so. The first fits of his anger are already being felt across much of the northern half of the country. Yet another Nor'easter is striking parts of New England. This storm brought us 3-6" of snow overnight, but parts of Maine will see over a foot.

In the Midwest, the National Weather Service (NWS) issued an 'Extreme Cold Warning' for parts of Minnesota last night. The Extreme Cold Warning is a new warning the NWS is trying out for temperatures lower than -40º. The warning surely verified, as temperatures this morning in International Falls, Minnesota got down to a mind-numbing -46º. Even Rochester, Minnesota, in the southern part of the state, dropped to -20º.

Some of the cold is on the way for us, but Old Man Winter has another shot to throw at us first: another bout of heavy lake effect snow. Schools across northern Cayuga, northern Onondaga and Oswego counties are dismissing early in anticipation of the lake effect blitz.

A huge contributor to heavy lake effect snow in a set-up like today's is whether or not moisture from the Upper Great Lakes is able to feed the Lake Ontario band. Observations from Canada this morning are indicating that the connection is being made, which only will increase the chances of heavy snow.

The lake effect will start up this afternoon and last into tomorrow morning before only gradually weakening and moving northward tomorrow. Some areas across Oswego, Oneida and northern Onondaga counties could see upwards of 2 feet by late tomorrow morning.

If that was not bad enough, the cold temperatures and winds will bring wind chills down to potentially dangerous levels late this afternoon and tonight. Even those not impacted by the lake effect will want to make sure they are properly bundled up against the cold.

This is all just the beginning though, and the next assault from Winter's War comes in Sunday and Monday. The bitter cold air mass that was over Minnesota this morning will work its way over us later this weekend.

High temperatures Sunday and Monday will struggle to reach 10º, and Sunday night will be the coldest night we have seen in a few years. Many areas across Central New York will see the mercury drop to -10º, and some of the outlying areas may even see -20º.

And now, could a grand finale to Old Man Winter's assault be in the works? The latest long range weather models are showing hints of another coastal storm in the works for the middle of next week. If the current model projections hold true, Central New York could be looking at its biggest widespread snow of the season so far. While it is way too early to tell whether or not that will come to pass, it will need to be watched as we head into next week.

On the bright least its not -46º!

Tuesday, January 18, 2011

Sleet & Freezing Rain- What's the Difference?

As posted on by Drew Montreuil, 1/18/11

With icy conditions impacting Central New York this morning, meteorologists have been tossing around words such as "sleet" and "freezing rain", but what are the differences between these icy precipitation types?

For my Honor's Program thesis at SUNY Oswego, I have been investigating how the general public interprets weather forecasts, and what terminology is and is not understood. One of the survey questions I used to gather this data directly relates to today's weather.

When asked what is the difference between sleet and freezing rain, my preliminary results show that only 16% correctly understand the difference. If you do not know the difference, do not feel bad- only a little over half of the meteorology majors I surveyed fully understood the difference!

So, just what is the difference? When the water freezes. Sleet typically starts out as a snowflake while it is in the cloud. As it begins to fall, it melts into a rain drop. However, the melting is brief and, before striking the ground, it refreezes. Thus, sleet is simply falling ice pellets.

Freezing rain, on the other hand, does not fall as ice. Like sleet, freezing rain often starts off as a snowflake in the cloud, and then melts as it begins to fall. The difference here is that there is enough warm air in the atmosphere to prevent the rain drop from freezing on its way to the ground. When the rain drop does reach the ground, it freezes, typically within seconds of contact. There is one important condition for this to happen though: the air temperature at the ground must be below freezing.

While both sleet and freezing rain can cause slippery roads, it is the freezing rain that is typically more hazardous. Since sleet is already frozen when it falls, it can be plowed and shoveled with relative ease. The freezing rain forms a coating of ice on roads, cars and power lines, making it much more difficult to remove. A few inches of sleet is not a huge deal, but even just half an inch of freezing rain can bring down trees and power lines and create a very dangerous ice storm.