2/24 PM Forecast Discussion

My apologies for having to post this here. The SUNY Oswego campus network has somehow decided to block all Grotonweather.com traffic from its network. I have managed to update most of the forecast as normal, but things such as the confidence forecast and uploading snow maps are impossible. Hopefully this will be fixed soon....in the mean time, we have a snow storm on our hands!

Forecast Discussion
A rapidly strengthening storm system over Arkansas will lift north and east, crossing across Pennsylvania tomorrow morning. The models are more or less in agreement with one another now, and they all keep the warm air and rain to the south. Despite this, I am still a tiny bit weary of the possibility of rain for Tompkins and southern Cortland County, as the rain/snow line will only be 30-50 miles to the south. I do have enough confidence to go with all snow now though. As I said this morning, since this storm is probably going to end up all snow, we are going to get it good. Below the discussion is the snow map I made for this storm. Most of the Grotonweather.com area is in the 7-14" range. Honestly though, I would not be at all surprised to see 16" or even 18" somewhere in that pink area. The snow will move in after midnight tonight and really become heavy for the morning hours tomorrow. By afternoon, the snow should begin to taper off. However, the winds will be on the increase, blowing all that fresh snow around. Significant blowing and drifting is likely tomorrow. I would likely be going into SNOW ALERT MODE if I had access to my files. Saturday and Sunday will each feature a shot at a few flurries, but nothing significant. Another storm will be in the works for Monday, but this one should remain all rain with the low tracking well to our west.


Storm total snowfall through Friday evening.

The Hype Machine

My good friend, classmate and colleague Evan Duffey posted a wonderful piece on Syracuse.com this morning. He has given me permission to repost it here. There are a lot of excellent points he makes about how big storms get blown way out of proportion through hear-say and media hype. Take a look:

Storm under-performs, public and media hype make it worse

For those of you wondering why you children's classes were canceled, or what happened to the 18"+ of snow you were expecting because your neighbors told you it would happen, I have your answer. The storm grew to massive size and intensity - in a special place I call overexcited media and populace. The storm, while no pushover, is not that epic, and should never have been treated as so.

In talking to fellow Meteorologist and Syracuse.com blogger Andrew Montreuil, he agrees he is upset at how this storm got hyped up.

While the storm will probably leave a decent impact on the area, talk of 18", 2 feet, etc. have been floating around either word of mouth or the internet. My max total event given during the entire even was 14".

Which brings me to a point I would like to bring up. A MAX snowfall accumulation is not what we expect, it's more then what we expect. When a meteorologist puts up a snowfall range, even I put a little extra on that top number just in case the unexpected occurs. Sadly the public takes this number as what they are going to get. For all of you interested in weather, try to remember this when reading forecasts and discussions.

Now to the meat - why did this storm under-perform even Meteorologists predictions for a storm? I hinted at the reason in a comment I made a few days ago, in my first post about the storm. I said "I think the upper limits of snowfall are possible only if warm, dry air doesn't work its way in too far North." This is pretty much what happened.

Radar overnight revealed a large dry slot was working into the storm. Dry-slots are almost always destructive to storms, taking away some of their thermodynamic strength, and obviously precipitation is hard pressed to be found in an area called a dry slot.

Blogger Drew Montreuil was involved in a Q&A session recently, and one of them really brings to light a lot about the forecast and expectations. Here is the quote:

...just in my day today I have overhead people talking about how we are supposed to get 2 feet of snow and such. These are over exaggerations. Often times, forecasts for big storms seem to take a life of their own. People mishear or misread things and, like a massive game of telephone, things get blown out of proportion. Another common mistake I see all the time is people assuming the high end of a snow prediction will be what happens. If there is a forecast for 6-12", but only 5" falls....it really is a decent forecast. But the hype before hand makes it seem like a bust.

To answer the question directly...I could see this "busting" slightly, yes. There are some indications drier air may work in quicker than what was earlier thought. This could bring the snow to an end a bit quicker, and keep us more in the 4-7" range instead of 6-10". Its a developing situation, and one can never be too sure they have the forecast nailed until the event actually happens...

Hopefully your day isn't too upset by the hype and over forecast of this winter storm, and please don't blame meteorologists. We aren't all that wrong.

Just how low did it go?

Original post appeared on Syracuse.com 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.