Winter Over? Not so fast...

Update: 1:30pm
I just wanted to add a comment here. I have been reached out to by multiple members of the Channel9 Storm Team to discuss this all further. Additionally, they posted a second post on their Facebook page to give greater clarification to their statement. This is why I started my blog post below praising the Storm Team meteorologists and expressing my great respect for them!

I've considered taking this blog down all together based on the conversations I've had with the Storm Team. I've decided to leave it up, however, because I do feel that public interpretation of forecasts is a crucial topic. I think this whole situation can shed some light on the topic for meteorologists and the public alike. Forecasting is difficult enough. Expressing the forecast to the public is another thing entirely.

Original Post:
Every once in a while, I come across a forecast that, quite honestly, makes my skin crawl. I try not to be judgmental about them- I've made plenty of bone-headed forecasts myself. At the same time though, sometimes something just needs to be said.

Let me preface my forthcoming rant with the following: I have a great deal of respect for the meteorologists at News Channel 9. I have met a number of them and they are great people. Their forecasts are typically very good and they are extremely intelligent. They do a great job.

Just not this time. This isn't meant to be an attack on them in any way, but the record needs to be set straight. It is February 17th. Historically, we could see significant snow well into April. (see April 16-17, 2007 for example). I cannot fathom how anyone can declare winter over at this stage, but that is what Channel 9 did:

First, let's look at the graphic that they are using to declare winter over. It is a probability map put out by the Climate Prediction Center for March, April and May. Areas in orange have a chance of seeing above normal temperatures, while areas in blue may see cooler than normal temperatures. Areas in white have an equal probability of seeing either cold, warm or normal temperatures. Let's zoom in and take a closer look at the Northeast:

Now, there are three possibilities for what can actually happen. We can be above average, below average, or right at normal. So in the white, "equal chance" areas, the probabilities of each of those three outcomes is about 33%. Each shade of orange/blue represents a greater chance of seeing warmer/colder temperatures. The Climate Prediction Center labels each shade with a percent value.  I have marked the 40% line, as it was a bit hard to see. Areas inside that 40% line, that is in the darker orange shade, have a 40% or greater chance of seeing above normal temperatures. The lighter orange shade, which includes Central New York, is predicted to have a 33-40% chance of seeing above normal temperatures. Given that the 33% line is very close to us, it can be assumed that it is more like a 33-35% chance.

That means we have about a 2% chance more than normal of seeing above normal temperatures.

Since the chances of a warm March, April and May are up by about 2%, and probabilities must add up to 100%, we can assume that the probabilities of a colder than normal March, April and May are running at about 31% and a normal period at 33%. Let's look at this forecast in another way:

Honestly, can you see much of a difference? Yes, we have a higher chance of above normal temperatures than anything else. But that increased chance is such a minor increase. If these were medical test results, would we want our doctors declaring definitely that the test was conclusive one way or another with a 35-33-31 distribution? I think not.

The other thing to consider is how accurate these probability forecasts are in the first place. The following as a graphic the Climate Prediction Center publishes along with their seasonal forecasts. It looks confusing, but I will explain it:

First, some background. There are numerous ways to calculate forecast accuracy. The Heidke Skill Score (HSS) is just one of those ways. A HSS of 100 means the forecast was perfect. A HSS of -50 is the worst possible forecast, and a HSS of 0 means the forecast was as good as a random guess.

We are looking at the red lines, which are labeled 'non-CL'. These 'non-CL' lines are the skill of forecasts where either colder than normal or warmer than normal forecasts are made. The year-to-year changes between these red lines are huge. You will notice a horizontal red line at 20. This is the average HSS for non-CL predictions from 1995-2008. The score is 20. Remember, a perfect forecast is 100 and a random guess is 0. A 20 is an extremely poor score and shows just how difficult it is to predict temperatures for the next three months.

Putting these two things together, we have a very slim chance of warmer weather based on a forecast that is much closer to a random guess than a perfect forecast.

With this knowledge, can you see why this upsets me? Meteorologists have an unspoken contract with the public to give accurate, informative forecasts. We have to do this to build trust between the meteorologist and the public. Why? Because when a tornado is bearing down on your neighborhood, or a major snow storm is on the way, or anything else that threatens lives and property, we need people to listen to us. Way too often, meteorologists, particularly in the media, betray this trust with garbage statements like this.

It needs to stop.

Now, I commented on that Facebook post and the response I got was "our forecasts are based on more than just what we are showing here- this graphic just happens to sum things up nicely." My argument is that 1) the graphic really shows nothing, as I explained previously and 2) there is no expression of uncertainty or these other factors. All that is said is 'winter is over.' I'm not against long-range forecasting. I am against long-range forecasts that don't express the inherent extreme uncertainty that they contain. And this is one of the worst offenders I've seen.

Might they end up being right? Sure. They might. If they are, was it skill or luck? I'll let you be the judge.

Arctic Outbreak?

We all knew it was probably only a matter of time before the weather finally turned more winter like. We got a taste of winter yesterday with some lake effect snow, strong winds, and temperatures in the 20s. While we have been warm lately, 500 miles to the north has been frigid. The chill yesterday and, to some extent, today, is just a small piece of that cold pool.

A much bigger piece will be breaking off next week. It will easily be the coldest air so far this season, with highs Tuesday and probably Wednesday staying in the teens. There will be wind. There will be snow. But will this be an 'arctic outbreak'?

There is no set definition for an arctic outbreak, so the use of the term is up to the discretion of the forecaster. It seems to me, however, that 'arctic outbreak' should be a term reserved for record setting or dangerous cold. It is a strong term that grabs people's attention. I do not think it should be overused.

Does the combination of high temperatures in the teens, gusty winds and lake effect snow meet these qualifications?  I am honestly on the fence.

On the one hand, it seems to me that highs in the teens are not all that impressive, given our climatology and the time of the year. Some lake effect snow and wind? That is just normal winter weather here.

Yet, on the other hand, this has not been a typical winter. We have only one high temperature under 30º (on the 24th...the high yesterday was actually 40, albeit that was at midnight). Snow has been scarce to non-existent. Being suddenly thrust into mid-winter weather may catch some off guard and create dangerous conditions.

In the end though, I think I would hesitate to use the words 'arctic outbreak' in my forecasts for the coming cold snap. I believe that the public should be aware that the pattern is changing and, at least for a few days, winter will be here in full.

But I do not want to sensationalize things and blow them out of proportion. This event, after all, is still nearly a week away. I've seen many extreme temperature events forecast this far out, only to have the models gradually and consistently modify temperatures back towards more normal temperatures.

I want to hear what you think though. Join the discussion and post what your definition of an arctic outbreak would be on Facebook by clicking here.

Respite Coming..But so is More Rain

 7:30 PM Update-

Unfortunately, the break in the rain I talked about 90 minutes ago below is filling in already. This means even more rain than I was expecting in the last post. That in turn means more flooding. Certainly not good news at all.

Wednesday- 6PM

For the past few hours, very heavy rain has been falling across our area. Major flooding is going on nearby, with some flooding also occurring within the Grotonweather area. Flash Flood Warnings are widespread across Central New York and Pennsylvania with numerous Flash Flood Emergencies and State of Emergencies in effect for neighboring counties. This will easily end up as the most destructive flood event in the region since the deadly June 2006 flood, which mostly missed the Grotonweather area, and may surpass that in some areas.

For all the bad, there is a little glimmer of good. The current band of heavy rain is quickly lifting to the north. By 7pm, we should be in another respite with just a few showers around. THIS DOES NOT MEAN THE FLOOD THREAT WILL DIMINISH JUST BECAUSE IT IS NOT RAINING. Runoff will continue to inflate streams, which will continue to rise and create major flooding in areas. The flooding just will not be getting rapidly worse.

Until the next batch of rain, that is. Models are indicating yet another batch of heavy rain streaming northward from the Mid-Atlantic. This rain should arrive here well after dark and during the overnight hours, making it particularly dangerous. Flooding dangers at night are enhanced because it is hard to see flood waters and impossible to tell how deep they may be (not that you really can in the day time either).

This is what the HRRR (high-res rapid refresh) model predicts the radar to look like at 11pm tonight. It looks a lot like what the radar has looked like most of the day, meaning more heavy rain will be impacting our area tonight.

If you have to travel tonight: take it slow, DEFINITELY DO NOT ATTEMPT TO CROSS A FLOODED ROADWAY, and be aware that many roads south and east of our area and some roads in our area are closed. For example, every road in Chenango County has been closed. States of Emergency, in addition to Chenango County, are in effect for Broome, Otsego, and Bradfield, PA, to name a couple.

If you live near a creek, stream, river, or drainage area: Chances are you already have an excess amount of water rushing through many times the normal amounts. Additional rain could increase the amount of water attempting to flow through there. Be prepared to have to leave your home at any time, even in the middle of the night. Keep an eye on the water levels as much as you can. If you have a weather radio, keep it on tonight. There are also lots of website that will send updates to your phone...you may want to sign up.

This remains a very dangerous situation, even while the rain lets up for a while. Please, please be safe. Continue to check the Grotonweather website, facebook and twitter pages for updates. Please share this blog with others so that they can stay informed and safe as well.