Late-May News and Updates

Hello Grotonweather Fans! I have been working very hard over the past couple of months on new and exciting things. I thought I would type up a blog to explain and promote some of these things.

First off is Finger Lakes Weather (www.fl-weather.com), my new weather forecasting and consulting business. It is my hope that Finger Lakes Weather will become my career, helping local businesses, organizations, and the public with private and customizable weather forecasts. Finger Lakes Weather offers a variety of "Forecast Packages" tailored specifically towards various groups. For the spring, I offered a frost forecast package and was able to do some free-trial forecasting for Fox Run Vineyards and Three Brothers Vineyards, both on Seneca Lake. I have plans for a forecast package for construction workers. Right now, I am offering a special on vacation forecasting...but more on that later. Check out Finger Lakes Weather (the website again is www.fl-weather.com) and join the Finger Lakes Facebook page.

Next up is the Grotonweather Radar Page (www.grotonweather.com/radar). I recently got some top-notch radar software that is used by many meteorologists, especially storm chasers and others interested in thunderstorms. This software allows me to upload the radar to the website, so that is what I have done. Furthermore, I can display things such as areas of possible hail, rotation in thunderstorms, winds, and watches and warnings. I can also zoom right in on a storm down to street-level. So far, this has been a HUGE success with hundred of views despite an overall quiet thunderstorm season thusfar.

A severe thunderstorm approaches Ithaca.

Success does not come without price, however. And in this case, the price is measured in bandwidth. For those not familiar, bandwidth is basically the amount of data transferred to and from a website. The radar page uploads large image files every few minutes and quickly ate up my monthly bandwidth limit. That in turn forced me to purchase a more expensive hosting plan. My costs for running Grotonweather.com, not including time spent, is now approaching $200 a year.

Since 2006, when I started this operation, I have not received any revenue from my website. I am dedicated to keeping the website free. As costs continue to rise, something has to be done to offset some of these costs. Rather than charge money for Grotonweather and rather than flat out asking for donations, I decided a fund-raiser would be the best idea.

This is where the vacation forecasting package from Finger Lakes Weather (www.fl-weather.com/vacation) comes back into play. As a fund-raiser, I am offering this service at a reduced price of just $10 per day or $50 per week. What does that entail? I will forecast for your travels to and from your vacation destination. I will forecast for you each morning of your trip so that you can know what to expect. If you have plans to engage in a certain activity- whether a day at the beach, a horseback ride, a bicycle tour...anything at all- I will forecast specifically for that activity and how the weather might impact your plans.

Furthermore, I will do severe weather forecasting for you. Say you are driving down the highway in Kansas and you see storms ahead. You can give me a call- no matter what time of day or night- and ask me if they are severe. Or, if you are enjoying your vacation (which you should be!), but storms (or a hurricane!) are coming, I will reach out to you and let you know.

I think this is a really neat and unique service and I believe it will help you make the most of your vacation. And it would really help relieve some of the costs I have. So please, consider signing up before June 10th to get the sale price. Even if your vacation is in August or later, book it now. Here is the link again: www.fl-weather.com/vacation

Moving on now, I am slowly working on a redesign of Grotonweather.com. I am really excited about how it looks so far. I did a survey a couple of weeks ago on displaying confidence and uncertainty in forecasts. The results were a tremendous help, so thank you to all who participated! I am now doing a smaller follow-up survey on a proposed forecast layout change. Please, if you could take a moment and fill it out, I would be very grateful. Here is the link: www.grotonweather.com/survey

If that was all not enough, I also started a new project on Facebook in an attempt to 1) combine my strong religious beliefs with my love for the weather 2) help those threatened by severe weather on a national level and 3) expand my forecasting beyond just the Finger Lakes. The result is the Storming Heaven Facebook group. If you believe in the power of prayer, go ahead an join up.

Back in late March, the Groton Public Library invited me to give an hour-long presentation. I presented on the Blizzard of 1993. Thank you to the library for the opportunity to speak! If you would like me to speak at your event or in your class (I've spoken at 3 schools since November), just send me an email or let me know on Facebook!

Thank you for reading this long post and for your continued support and interest in Grotonweather.com and the other projects I am working on. Stay tuned for more great features coming up...I am only getting started!!!

Hold the Hype, Please

For the past few days, the models have been very inconsistent with one another, and from run-to-run (meaning the morning version of a model disagrees with the same model's afternoon version which disagrees with the night version and so on). The problem storm is a nor'easter that is expected to develop over the Gulf of Mexico before storming northward on Monday. Some models had been pushing the storm off the east coast, while others bring it further inland. As is always the case with these types of storms, the track is everything.

The evening models last night (Thursday) finally showed some agreement with a more inland track. This had some major implications on the meteorological community: the hype machine was put into full throttle. To understand this, and the forecasts that are gushing out, the public needs to glimpse into the mind of a meteorologist for a moment.

Most of us love storms...it is just part of our nature. Active weather is exciting. Unseasonable weather gets our adrenaline pumping. Average temperatures and sunny weather are, dare I say, boring. So when there is a big storm on the horizon, there is always a temptation to sensationalize it and force our predictions into more of what we want to happen and less what the models actually say will happen. This is called 'wishcasting'.

It is difficult not to wishcast, and it is something I struggled with a lot during the early days of Grotonweather. I easily got caught up in hype and would force situations to what I wanted to happen. I would latch onto little parts of the model that supported my desire, and ignore larger parts that would indicate I was about to make a bad forecast.

So when the models came into some semblance of agreement last night, the floodgates were opened. Many now felt justified in making big predictions-- after all, the models are all agreeing now!!

Hold the hype, please.

This is a nor'easter we are talking about, a proverbial thorn in the side of meteorologists for as long as they have been predicting weather in the Northeast. The models three days out for a nor'easter often do not capture the details that make or break the storm. Sometimes even the models a day out are no good. Consistency is the key. Just because the models yesterday evening agreed does not mean they will not disagree again this morning, afternoon or evening. It would be wise to see a few more runs of consistency before calling for a monster storm.

But now, to the wishcasting.

As I said above, meteorologists love active, out-of-season weather. What is more out of season than a heavy snowstorm in late April? And that is exactly what some meteorologists are calling for over parts of the region. However, given the current models, I feel such a forecast is uncalled for. Could it happen? Sure- history shows it can. I just do not think anyone is justified in making that call yet.

The first problem is the "540 thickness line". Meteorological jargon for sure, but let me explain. One of the (many) equations we have to learn in school related the average temperature of the atmosphere above a given point to the pressure at certain levels in the atmosphere. A warmer atmosphere will cause higher pressures, and thus a "thicker" atmosphere.

There are certain rules of thumb for how "thick" an air column above a point can be before the air is too warm for snow. One of those rules is the 540 line. To keep things simple, it suffices to know that values below 540 are favorable for snow and values above 540 are going to be rain. This rule has a catch though: it works best in the dead of winter. In late fall and early spring, values at or just below 540 probably are going to be rain, or perhaps a rain/snow mix at best. I like to see values closer to 534 before I get excited about snow.

Let us now look at Monday morning at 8am, the time that many meteorologists are posting images of the models for. Surface temperatures will be coldest at this time, with daytime heating kicking in for the afternoon Monday.

Major snow storm? The models don't think so.

As you can see, these three major models all indicate little, if any, snow confined to the far western fringes of the storm. Additionally, temperatures have been unseasonably warm all winter and spring. The ground, therefore, is also unseasonably warm. Late April storms of the past (2007 and 1993 for example) have come following very snowy years where the ground was likely cooler than normal. I have a hard time believing snow would accumulate very easily except perhaps over the highest elevations unless it got very cold (surface temperatures in the 20s).

Models try to directly guess the precipitation type and snowfall amounts, and some will undoubtedly point to those model outputs as their justification. (The NAM model, for example, has 6" of snow in Ithaca on Monday). Those model predictions are basically made by taking the model predictions, putting them through more equations and conditions, and then trying to make a new prediction. They can be useful, but the more processed the model data is, the greater the opportunity for error. The precipitation type and snowfall amounts, especially from the NAM model, I have found to be rather unreliable this spring. A few weeks ago, this same model insisted on bringing Ithaca another storm of 6-12". It rained.

In conclusion, this is what I want the public to take away from this. We don't know what will happen yet. Confidence is low and this system needs to be watched. While I enjoy the loyalty my patrons have to Grotonweather, I encourage them to look at other forecasts, too. I have been wrong before and will be again in the future.

What I want other meteorologists to take from this is as follows: we, as a meteorological community, need to focus more on uncertainty and communicating that in our forecasts. We need to cut the hype and sensationalizing every large storm. There are times when we NEED to really play up a storm- like last weekend's tornado outbreak. There was a lot of justified hype last weekend and it saved lives. This weekend's hype is not justified. Where do we draw that line? It is impossible to say for sure. But I can say it needs to be drawn better than it currently is, or when it does matter, people are not going to listen.

Fire and Ice

 Reposted from Finger Lakes Weather:

The Finger Lakes area will be under assault from fire and ice over the next two days. It sounds like Armageddon, and while it certainly is not, these are serious risks that need to be addressed.

A large area of high pressure is building into the region from Canada. The air with this high is extremely dry. With a lot of the vegetation still not growing, coupled with a general lack of significant precipitation over the last days, weeks and even months, this dry air will only continue to dry things out. The strong April sun will be out full force during the day. This will heat the ground, which will cause the air to rise. New air will rush in to take its place in the form of strong, gusty winds. Not only will the strong winds quickly fan any fires that do pop up, but the wind helps dry vegetation as well.

Because of this high fire risk, burning is strongly discouraged and extra care needs to be taken with any open heat source. This includes cigarette butts and welding sparks. It will not take much for a fire to start and quickly spread. Any brush fire has the potential to spread to buildings and put our firefighters, and the public, at risk.
As the sun sets, two important things happen. First, the ground is no longer heated, which causes the winds to die down. Second, the temperatures begins to fall, which increases the relative humidity in the atmosphere. While this effectively reduces the fire risk, it opens the door for frost and freeze conditions. Generally, Saturday morning will be as cold as Friday morning, within a couple degrees on either side. If you needed to take precautions against the cold this morning, you will want to repeat your efforts for tomorrow.

Saturday afternoon, we continue with another very high fire risk. By Easter Sunday, our problems will begin to lessen. Some moisture will work in, keeping our relative humidity higher during the day and our fire risk subsequently lower. This moisture should also increase the clouds into next week, keeping our nighttime low temperatures up. There are still a lot of details that are unknown next week, but it looks chilly. Check back Monday for a new blog, and have a happy Easter!

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.