Wunderground Meteorologist Shaun Tanner

New Year's Weather and WunderCast

By: shauntanner, 10:18 PM GMT on December 29, 2009

This is one of your last reminders that the WunderCast Forecasting Competition will be starting NEXT WEEK. The WunderCast Competition is for people who want to learn about forecasting, or for people who like to brag about their forecasting skills. To learn more about the competition and to sign up for it, visit here. Keep in mind that it is free to enter and we are playing simply for bragging rights. The first forecast day is January 5th and we are forecasting for Burlington, Vermont (KBTV).

So we are only a couple days away from the annual tradition of watching the ball drop in Times Square. It seems like I have watched Dick Clark (and more recently, Ryan Seacrest, I saw reluctantly) for decades stand in Times Square on frigid New Year's Eve and county backwards. Every time, the obligatory comment in the form of "look at all these people standing in the frigid winter air that greets us every New Year's Eve..." I roll my eyes at the thought of treating the thousands of people voluntarily standing in the "supposed-to-be" cold air as weary soldiers. I laugh during the years when it is actually seasonally warm and this statement is still uttered. You watch, SOMEONE will say it this year.

Since we are talking about it, what is the weather forecast for Times Square this year? Well, the answer to that is, quite seasonal. And don't let Mr. Seacrest tell you any different! If you look at the hourly forecast, you will see that temperatures will be dropping (of course) along with the shiny ball around midnight. Temperatures around midnight are expected to be just slightly above freezing (32 degrees) with somewhat of a possibility of rain changing to snow after midnight. So, not terrible.

Let's take a look at where it WILL be terrible on Thursday night, instead. Take a look at the forecast for Fargo, ND. Wish you were there? Brrrr, with temperatures dropping from 0 degrees at 6 p.m. to a bone-chilling -8 degrees when the clock strikes a new year. Ouch.

If you are looking for warmer weather, then settle for the naturally boring weather in Key West, FL. Temperatures in the mid-70s at midnight will suit you just fine.

What type of weather is perfect for your New Year's celebration?


Past Christmas Weather

By: shauntanner, 6:33 PM GMT on December 22, 2009

Along with the blog I posted yesterday (below), I am adding to it with one of my favorite Christmas pieces. Every year I force my family to break out the old "John Denver and the Muppets" Christmas special and album. On it is a piece about Alfie the Christmas tree. I hope everybody has a wonderful rest of the week, and thank you for another good year here at Weather Underground. Here is Alfie's story:

Did you ever hear the story of the Christmas tree?
Who just didn't want to change the show
He liked living in the woods and playing with squirrels
He liked bicycles and snow

He liked wolves and eagles and grizzly bears
And critters and creatures that crawled
Why bugs were some of his very best friends
Spiders and ants and all

Now that's not to say that he ever looked down
On a vision of twinkled lights
Or on mirrored bubbles and peppermint canes
And a thousand other delights

And he often had dreams of tiny reindeer
And a jolly old man in a sleigh
Full of toys and presents and wonderful things
And a story of Christmas day

Oh, Alfie believed in Christmas alright
He was full of Christmas cheer
All of each and every day
And all throughout the year

To Him it was more than a special time
Much more than a special day
It was more than a beautiful story
It was a special kind of way

You see some folks have never heard a jingle bell ring
And they've never heard of Santa Claus
They've never heard the story of the Son Of God
And that made Alfie pause

Did that mean that they'd never know of peace on earth
Or the brotherhood of man
Or know how to love, or know how to give
If they can't, no one can

You see, life is a very special kind of thing
Not just for a chosen few
But for each and every living, breathing thing
Not just me and you

So when you're at Christmas prayers this year
Alfie asked me if I'd ask you
Say a prayer for the wind and the water and the wood
And those who live there too


I have done my due diligence and compiled the national average high and low temperatures for every Christmas since 1950. The simplicity of the numbers are my biggest obstacle, as all I did was take the maximum temperature for for ICAO in the country to obtain an average. I did likewise for minimum temperature. So, the average may not tell the whole story if one side of the country is in a historical cold spell while the other is baking in record heat. In this circumstance, while it would be a noteworthy Christmas, the average high and low may just show a normal Christmas day. Nonetheless, I think it is interesting to take a look at.

Coldest Christmas
What was the coldest Christmas since 1950? This question has many answers. Some may define it as the Christmas when the coldest ever Christmas temperature occurred. If that was the answer to the question, then the coldest Christmas was 1996, when -40 degrees was recorded at Flag Island in Minnesota. You can see that on that day, observations were only taken to 10 a.m. and the high temperature during that time could only manage to get up to -29 degrees. There were also other frigid temperatures Christmas Day 1996. Glasgow, Mont. dropped to -35 degrees, Baudette, Minn. plunged to -35 degrees as well, and International Falls is typically cold and it recorded a temperature of -34 degrees that day. These areas are all located in the northern part of the country so it is safe to say that there was a cold, Arctic outbreak that day. But, some may say the coldest Christmas would be defined as the day with the coldest average low temperature throughout the country. If this was the case, then the correct answer would not be the 1996 day that I just discussed. In fact, the average low temperature on Christmas 1996 was 17 degrees. The Christmas day that had the coldest average low temperature since 1950 was...1983. On that day, the average low temperature was 8 degrees. That is astounding. Think about it. The average city in the country on Christmas Day 1996 had a low of 8 degrees. A general look at the low temperatures that day shows cold air in the typical locations in the north, but also far south into Virginia, Iowa, and other places to the south.

The cold temperatures were so prevalent that day, that 1983 blew away any other contenders for coldest Christmas Day. Take a look at Figure 1 to see what I am talking about. You can see the upside-down spike that represents the year 1983. What makes this spike even more pronounced is that the years on either side of 1983 somewhat high. The year 1983 also holds the record for the lowest average high temperature with a value of 20 degrees. Again, astounding. That means that the average city in the country on that day could only manage a high temperature a dozen degrees below freezing.

These stats were so startling that I had to go search for a surface map analysis for that day. And I found it. Figure 2 is the surface analysis for Christmas Day 1983. You can see that as far as precipitation goes, that day was not all that impressive. Some snow in the Northeast, Great Lakes, and Rockies, but that is about it. Instead, you have frigid air for much of the country. Take a look at the temperature gradient from Arizona to New Mexico. That gradient is the difference between a nice Christmas Day in Phoenix where the temperature was 58 degrees and a starkly cold Christmas in Roswell, N.M. where the temperature was 9 degrees. This cold air stretched throughout the rest of the country with temperatures of 4 degrees in Amarillo, Texas (TEXAS!), -9 degrees in Des Moines, 3 degrees in New York, and even 22 degrees in Orlando. These temperatures are startling. Just take a look at the map in a larger version if you need more proof. Temperatures in the mid-20s in Florida, low 10s in Georgia, and below zero from Oklahoma City northward.

Farther down on Figure 2, you will see the 500 mb analysis for that day and you can get an idea of what led to such a cold outbreak. An intensely deep trough of low pressure over Maine and eastern Canada allowed cold air to pour into the East. The West Coast was spared the cold air from a ridge of high pressure, but a low did bring rain to coastal California.

Warmest Christmas
Unlike 1983 when there was a definite cold Christmas, there are no Christmas Days since 1950 where the average temperature spike into the 70s or 80s. Instead, the highest average maximum temperature occurred on Christmas 1955. This year also tied with 1964 for the highest average low temperature. The average high temperature for 1955 was 56 degrees. Not too bad. However, the hottest Christmas temperature since 1950 was recorded on that day when Laredo, Texas soared to 91 degrees. That is not exactly a White Christmas. Several ICAOs recorded temperatures of 90 degrees or higher that day, but all of them were in Texas.

Anyway, I found all of this interesting.

Figure 1. The national average high and low temperatures for Christmas Day since 1950

Updated: 6:08 PM GMT on December 23, 2009


Skeptical Of The Skeptics

By: shauntanner, 6:24 PM GMT on December 17, 2009

I am wading back into the tepid Climate Change pool today because it is topical and I enjoy being lambasted in the comments.

If you managed to pull yourself away from playing "Modern Warfare 2" these past few days, you most likely have heard there is a big climate summit going on in Copenhagen. The summit has been marred by disagreements inside and protests outside. I am always amazed violent protesters think their tactics will force the powers-that-be to be swayed in the direction of their cause. After reading Martin Luther King Jr's biography, I am equally amazed by his resolve to the non-violent civil disobedience movement. In the face of the threat of incredible violence and oppression, he stuck to the non-violent way and gave birth to most likely the largest single movement in America's history. So, it is my opinion that these current protesters in Copenhagen are approaching their protests incorrectly. Clearly they are passionate, but it's the wrong approach. For example, recently the University of California voted to increase tuition in the school system substantially. In response to this, some angry students (and some non-students, figure that out) significantly vandalized a University's chancellors house. So, let's see how this makes sense. In an attempt to overturn the tuition hike, these students come to the conclusion that violence would get them to their goal. Not only do they do themselves a disservice, but now the true, non-violent anti-tuition hike movement has been set back and will not be taken seriously.

More personally, my wife is terrible when dealing with customer service. She will walk into a store trying to return some items and in the matter of only a few seconds be yelling at the poor customer service people when she does not get her way. Not only is it embarrassing for me should I happen to be with her, but it is completely counter intuitive to her goal. No customer service person wants to be yelled at, and no customer service person can change the return policy of a company. Rather, the non-violent way is a better way, I tell her. If a company has a policy you do not agree with, don't shop there...period. If enough people agree with you and stop shopping at a store, then things will change. It just makes more sense. Sure, I am ridiculed at home for my substantial "banned stores" list, but at least I am happy at the stores I do shop at.

Back to Copenhagen. These protesters will not get anywhere with their current tactics. Nobody likes a whiner. Rather, they should concentrate on tactics that actually do work. Support companies that align with their values. Visit countries that understand Climate Change and the need to reduce. If enough people agree with you, things will change.

Skeptics...Be Creative
As soon as the Copenhagen summit began, I began to see headlines on various skeptic sites such as "Blizzard Dumps Snow on Copenhagen as Leaders Battle Warming...", "Journalist Complain About Cold in Denmark", etc. This tactic is an underhanded way of bringing doubt into very serious talks that will have the capability of changing the world, one way or another. This drives me nuts. I understand the energy some skeptics have put into research and vast understanding of the "debate", but such hit-and-run tactics are non-scientific and downright ignorant. I should not even have to say this, but to take one example of weather on one specific day to make a point about climate change is not accurate. Climate Change has to be referenced in terms of...climate. Since climate is the long-term study of averages and trends, by definition "Snow Forecast for Copenhagen" in no way should enter the argument against Climate Change.

Distraction has long been the tactic taken by Climate Change skeptics. Rather than attack the message, they attach the messenger. Instead of attacking Al Gore's message, they attack his energy use, his financial investments, and his lifestyle. Instead of finding evidence that Climate Change in itself is not manmade, they hack emails and post them on the internet. Like the violent protesters in Copenhagen, these types of tactics turn me away from the actual movement of the the real Climate Change skeptics.

On the other side, Climate Change scientists use actual data to make their points. This, obviously, is a more substantial way to prove your point. Actual facts and data go a long way.

Don't tell me that Al Gore uses a lot of energy. Instead question the slight cooling in the middle of the 1900's and the expansion of such glaciers as the one on top of Mt. Shasta. Those are specific examples that should be studied and are valid in the Climate Change "debate".

Lastly, I hope beyond hope that the skeptics are correct. Them being correct means that Climate Change is not necessarily man-made if real at all, and we can all go ahead with our happy, destructive ways. If they are wrong, we have to make significant changes in our lifestyle just to maintain a world that I love. But if they are wrong, the longer we wait, the worse of it will be for us. So, doesn't it make sense to make sustainable decisions now, rather than later. Doesn't it make sense to save a little energy here and there, pollute just a little less, consume just a little less, and be just a little more aware if it means the health of our planet?

Updated: 6:30 PM GMT on December 17, 2009


Another Storm Set For West Coast

By: shauntanner, 5:43 PM GMT on December 15, 2009

Remember, you can register for the WunderCast Competition by going here.

Another Pacific storm is set to smash into the Northwest coast on Wednesday. A look at the radar shows that the storm is already here with precipitation near the Washington/Oregon border and more rain off the coast of California near Eureka. Widespread Winter Storm Warnings are in effect for much of the Intermountain West in anticipation of the freezing sort of precipitation.

The most recent satellite shows a mass of clouds moving onto the coast with a definite boundary behind it marking the main cold front. This cold front is expected to sag slowly southward into Northern California. But, because the front will kind of have an east to west orientation, it will make it difficult to forecast. The reason is, if the front takes a bit more southern route, then many more areas will receive precipitation than what the models project. The GFS is predicting a southward jog of the front into Central California on Wednesday, with the Bay Area and Sierra Nevadas getting another dose of precipitation then. But, it could push southward soon and provide more, longer rain.

As is often said around these parts, any snow is good for the current drought California is going through because that snowpack eventually because our drinking water. Current snow depth data shows a strong early season base for many locations, so keep the snow coming!

It's Never Too Early To Predict Christmas
I have never, ever been a proponent of long-term forecasting. And by long-term, I mean anything greater than 7 days out. The unknowns are just far too great and as a meteorologist you risk being called out for your bad forecast. But, that won't stop me looking forward to Christmas weather!

The current GFS is showing a downright frigid Christmas for the northern portion of the country and a cool to chilly Christmas for the West Coast. A snowstorm is possible in the Rockies while the West Coast is expected to be dry. This all changes when you look to the east as a major storm develops. This will not be a tremendously cold storm, but it has the capability of producing widespread precipitation east of the Mississippi.

Now, remember, everything will change. The forecast I just mentioned above will change. So perhaps in a few days I will give you an update.

Updated: 6:18 PM GMT on December 15, 2009


White California Christmas

By: shauntanner, 7:13 PM GMT on December 09, 2009

Remember, you can register for the new WunderCast Competition by going here.

A major storm is currently slamming the East with intense wind, heavy early season snow, and cold temperatures. But, as is common with these types of storms, it originated in the West. This storm brought cold temperatures that are still lingering in its wake and very low snow levels.

As you can imagine, low elevations of California are not accustomed to White Christmases. In fact, they are downright rare if not non-existent. To go beyond that, if it snows ANYTIME here in San Francisco it is a major event. Not to mention the fact that people will go crazy here if it does snow.

But this storm brought the closest thing I can imagine to a White Christmas for the Bay Area and other parts of California. Although it is still two weeks before Christmas, I cannot imagine getting anything closer by then. I woke up Tuesday morning knowing the snow level would be pretty low. I live in a valley so it was very unlikely to get any snow in my front yard, but snow on the foothills was down to 300 feet. One of my co-workers brought in a photo of his front yard in which a thin blanket of snow was seen. He lives in the East Bay at a couple hundred feet of elevation. This is quite remarkable for any time of year let alone before Christmas. Our coldest month is normally February and this is when we get our lowest snow levels.

But, I consider this all good news because low snow levels here mean significant snow in the Sierra Nevadas. Snow up there not only represents a good skiing season, but it means a dent in our drought. A look at Snow Depths in California shows a couple feet of new snow in many locations. This is a good amount of snow before the beginning of the year.

More on the way
Several more storms are set to slam into the West between now and Monday, but I don't think any one of them will be as cold as the one that just passed. They may be wetter, though. This will translate to more precipitation and normal snow levels of several thousand feet. Again, nothing but good news to the reservoir coffers.


WunderCast Registration Is Open

By: shauntanner, 6:11 PM GMT on December 08, 2009

I have now opened registration for the WunderCast competition. You can register at the WunderCast Home Page.

Remember, the actual competition does not begin until Tuesday, January 5th so you have plenty of time to study the cities we will be forecasting for.

We will be forecast for Burlington, VT (KBTV); Redding, CA (KRDD), and Anchorage International, AK (PANC). I am hoping for a wild, cold ride that will keep everybody on their toes. The competition will basically last through part of February so it will be much shorter that the previous competitions. If you are a novice forecaster, no worry. There will be plenty of people to teach you, and you will have this blog as a reference. So join up!

Contest rules and info follows:


Think you can forecast better than the person on the television? Want to learn how to forecast like a professional meteorologist? Join the WunderCast Competition!

Weather Underground presents the WunderCast Competition, a friendly competition between weather enthusiasts to determine the best of the best in weather forecasting. Don't worry if you do not have any experience in forecasting, learn from Weather Underground meteorologists as well as experienced website community members to become an expert forecaster. Help Weather Underground create a closer community and join the competition!

WunderCast Competition Rules:

The WunderCast competition is run solely by Weather Underground, Inc. and all contestants agree to the rules within. Weather Underground reserves the right to change or add rules at any time. All disputes will be settled by Weather Underground.

A forecasting day will be midnight to midnight (12 A.M. to 12 A.M.) local time of the current forecast city. For instance, if the current forecast ICAO is KNYC (Central Park, New York), then contestants will forecast a high temperature, low temperature, and percentage of precipitation category for the period from midnight to midnight eastern time. If the current ICAO is KLAX (Los Angeles International Airport), then the forecast period is midnight to midnight pacific time. The schedule can be found by clicking on the Schedule tab. Contestants will make forecasts for Tuesday through Friday.

For each forecast period, contestants will enter a high and low temperature (both in Fahrenheit), and a percentage from 1 to 100 that indicates a chance of precipitation. These values should be entered on the Submit Forecast tab.

Scores will be calculated by taking the difference between a participant's forecast and the verified weather for a given day. For temperature forecasts, the error contributes directly to the number of points accrued for the day. Points for precipitation are determined by dividing a participant's error by 10. These raw scores are then normalized to ensure fairness and a competitive contest.

No charge to enter. Void where prohibited by law.



WunderCast Forecast Cities!

By: shauntanner, 9:29 PM GMT on December 02, 2009

I have decided to start the next edition of the WunderCast Competition on January 5th, 2010. I have taken the advice of some of the competitors and slashed the number of cities in the competition to 3. So, the competition will be only 6 weeks total. Hopefully, that will keep people in the race for the whole deal.

I will open up registration next week on Tuesday and leave it open right up until the competition start date.

I have also decided on which cities we will be forecasting. Here they are:

January 5th through January 15th: KBTV (Burlington International Airport, Vermont)
January 19th through January 29th: KRDD (Redding Municipal Airport, California)
February 2nd through February 12th: PANC (Stevens Anchorage International Airport, Alaska)

Let the bickering begin!


Tis The Energy Busting Season

By: shauntanner, 5:51 PM GMT on December 01, 2009

Well, December 1st has finally (at long last) arrived and suddenly my radio is taken over by the 24-hour Christmas songs spanning decades. Actually to be honest, I like the all-Christmas channel. It reminds me of childhood when life was good and the planet was far from my mind.

But now, I am an adult, shouldered with heavy obligations like children, mortgage payments, and saving the planet. With regard to planet-saving, I consider myself moderately well-informed in comparison to other climate scientists and very well-informed in comparison to the general public. As such, I have taken several steps in my life to combat my family's carbon footprint; recycling water, replacing light bulbs, planting trees and plants, etc. But this time of year is hard for me. I am stuck in the cycle of my childhood. Just this weekend, as is custom, my family trekked up to the Santa Cruz Mountains to cut down a Christmas tree. Following this, my father went up to his attic and brought down an army of Christmas decorations for inside and out. My house is slightly more conservative, with only the trim outlined in white Christmas lights. Be it laziness or actual concern about the complete waste of electricity, I cannot seem to get myself to put up a blowup igloo with dancing penguins.

But therein lies the problem. As the planet-crusader scientist I try to be, the correct thing to do this time of year would be to cut back on electricity even more to compensate for the my father's electronic, moving deer that surround the lake of blue lights. Instead, I found myself crawling to the top of my roof yesterday, flat on my stomach while clinging to my moss-covered tiles while stretching to put up the last of my string of lights.

The huge Christmas tree in my living room is another remnant of Childhood. The Christmas tree farm we went to had to be clear-cut years ago to make way for these trees. Then, the very act of cutting down that tree releases carbon dioxide as it does when it decays. But, buying some plastic or other manufactured material tree is not really any better than cutting down a tree.

My point here is, to celebrate the season, how does an environmentally conscious scientist do it?


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Wunderground Meteorologist Shaun Tanner

About shauntanner

Shaun Tanner has been a meteorologist at Weather Underground since 2004.

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