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Winter Forecasting: Indigenous Prognostications and Old Wives’ Tales

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Long before The Game of Thrones made “Winter is coming,” a hashtag, people have been looking for ways to predict how cold, snowy, wet, warm, or long an impending winter might be. As we head into fall, I thought it would be a nice break from talk of hurricanes and disasters to review a few of the more popular and interesting ones.

little bird, big snow

A little bird searches for seed under a birdfeeder in the author’s backyard on December 26, 2016 after a big snow by Raleigh’s standards.

Persimmon seeds

This one popped up on my Facebook feed, yesterday, and it’s one I had never heard of. Maybe that’s because I haven’t lived in the Ozark mountains where persimmons must be somewhat popular trees. (I have to admit, I even had to look up whether the fruit was edible.)

According to a post on Buffalo National River’s Facebook page:

Early settlers of the Ozarks would often predict winter weather using a persimmon seed. If the kernel inside the seed was shaped like a spoon, they predicted an abnormally wet and snowy winter. If it was shaped like a fork, they would expect some dry, powdery snow and a mild winter. If it was shaped like a knife, they said that icy wind would “cut” the winter air.

Based on the photo that goes with the post (follow the hyperlink to see it), the Ozarks might expect “an abnormally wet and snowy winter.” Someone, please remind me to see how that turned out next spring.

Woolly worms

North Carolina folks will be more familiar with this one because Banner Elk has an annual Woolly Worm Festival in October. According to the website allaboutworms.com, the wooly worm is a caterpillar that becomes a tiger moth. “In the American Northeast, it is believed that if the woolly worm has more brown on its body than black, it will be a fair winter. If the woolly worm has more black than brown, the winter will be harsh.”

For the record, last year’s Woolly Worm Festival winner was named Hans Solo, and according to the festival’s website, he predicted week 1 to have normal temperatures with light snow, weeks 2-4 to have below normal temperatures with accumulations of snow, weeks 5-11 to have above normal temperatures with little or no snow, and weeks 12-13 to have average temperatures with light snow.

How did the winter turn out?

Looking at Sugar Mountain Resort’s snow history for the season, there was no snow reported the first week of winter, 22 inches of snow during weeks 2-4, five inches in weeks 5-11, and none recorded during weeks 12-13. For the science-minded and curious, according to the National Weather Service’s archived data for Asheville, which is the closest NWS climate reporting station, December 2016 had below average precipitation, January had slightly above normal precipitation (by 0.72 inches), and February and March had below normal precipitation. All four months experienced above normal temperatures.

The Farmer’s Almanac’s signs of a hard winter

The Farmers’ Almanac is famous for folklore and unscientific predictions about winter. One blog post from 2008 lists “20 signs of a hard winter.” A few that I have noticed here in Wake Forest that happen to be on the list: thicker than normal corn husks, heavy and numerous fogs during August, and spiders spinning larger than usual webs and entering the house in great numbers (shudder). Of course, the only one of these that is scientifically verifiable – as opposed to being based upon memory of past encounters with web-spinning spiders and how thick corn husks seem to be when I shuck my own corn – is “heavy and numerous fogs during August.” If you drive over the Neuse River as early in the morning as I do, you may have noticed those foggy mornings, too.

The Climate Prediction Center uses real science

To contrast woolly worms and creepy arachnids, I like to look at the Climate Prediction Center’s forecast, and I like to keep in mind that 3 months in advance, I don’t expect a great deal of accuracy from it either. The CPC considers things like El Nino/La Nina, global trends, and other large scale oscillations when making long-range seasonal forecasts. The forecast for the months of December through February show above-average chances for above-normal temperatures for most of the country including North Carolina, as well as mostly equal chances for average precipitation. In plain English, that means we will probably have a warmer-than-normal winter with about the usual amount of rain and snowfall.

Truly, only time will tell how this winter stacks up.

Weather Blog

Irma – an interesting case study in forecasting

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As of this morning, Irma has weakened to a tropical storm, but don’t let the downgrade fool you. She’s still packs a punch with sustained winds up to 65 mph and heavy rains. Her tropical-storm-force winds extend outward up to 415 miles from her center, so her reach is still huge. For that reason, tropical storm warnings extend up both sides of the Florida peninsula and along the coasts of Georgia and South Carolina. Irma will be a tropical depression by tomorrow morning, and nothing more than remnants by the end of the week.

Now that the worst of the storm has subsided, I thought it would be interesting to look back at some of the forecast updates from last week. This post will be a bit graphics-heavy, but for those with short memories like mine, the graphics will be helpful.

On Tuesday, September 5, the 11 a.m. advisory graphic showed Irma passing over the northern Leeward Islands, Puerto Rico, the northern coast of Hispanolia, and possibly most of Cuba before reaching the Florida Keys. The forecast cone for 8 a.m. Sunday was actually centered on the Keys as Irma started her expected turn toward the north.

20170905 graphic

Irma’s September 5, 2017, 11 a.m. forecast track.

On Thursday, September 7, the 2 p.m. update had shifted the track slightly eastward so that by Sunday morning, Irma was making landfall near Miami. Some feared the worst as Homestead, Florida, which took the brunt of Hurricane Andrew, appeared to have become the target for Florida landfall. By that time, Irma had pasted Puerto Rico and was heading toward the Bahamas. The norther coast of Cuba was under a Tropical Storm Warning.

The 5-day track showed Irma still being a tropical storm by 8 a.m. Tuesday (tomorrow) morning, passing over the western part of the North Carolina/South Carolina border and bringing high winds, heavy rain, and possibly isolated tornadoes to much of NC.

20170907 graphic

Irma’s September 7, 2017, 2 p.m. forecast track

On Friday, September 8, the 8 a.m. forecast update, showed Irma affecting the Bahamas, northern Cuba, and central Southern Florida as a major storm. Truly, the tip of southern Florida was where the center of the cone was located. Irma was expected to take her time moving up the center of the Peninsula, into Georgia as a tropical storm, and then up to central Tennessee as a tropical depression by Wednesday morning.

20170908 graphic

Irma’s September 8, 2017, 8 a.m. forecast track

Jump forward to today, and we see Irma is a strong tropical storm moving through the panhandle of Florida, about to cross into Southern Georgia, and eventually through north-central Alabama, northeastern Mississippi, and into western Tennessee.

20170911 graphic

Irma’s September 11, 2017, 2 p.m. forecast track

If you look at this morning’s wind history map and compare it to the above maps, one fact will likely jump out at you. That forecast track from last Tuesday seems to have been the closest to her actual track and landfall overall. It’s almost uncanny!

20170911 wind history

Irma’s wind history as of the morning of September 11, 2017.

Before you rush to judgement, though, and say the National Hurricane Center should have stuck with that forecast all along, let’s think about some of the many things they consider when making these forecasts:

  1. Multiple numerical weather prediction models with multiple variations on many of them. Some are run hourly, and others run every 12 hours. Each has its own strengths and weaknesses, and each accounts for some variables in the atmosphere, but not others. It’s the forecasters’ jobs to know which tends to be the best for which type of weather.
  2. Data being added by the Air Force Hurricane Hunters’ flights through and around the storm. Their real-time information help NHC forecasters determine the actual pressure, winds, and steering currents of the storm (among other things). The information they gather is invaluable to forecasters.
  3. The way hurricanes interact with land and the ocean are very different. Both play a role in the strength of the storm. Land tends to weaken storms while warm ocean waters strengthen them.
  4. Other low and high-pressure systems in the general region (North America and the northern Atlantic) greatly influence the track of the storm. The models showed a turn toward the north, but the timing of that turn greatly depended upon the timing of the movement of a high-pressure system that was blocking that turn. Some model runs rushed it, and others slowed it down.
  5. All the things that we know we don’t know. The National Hurricane Center archives and eventually verifies its forecasts. In fact, a page of their website explains their methods for verification and shows their accuracy for track and strength for the years 2012-2016. Verification is part of the scientific method. It helps forecasters track their progress in improving their own forecasts. After all, you can’t get better at something if you don’t have a grasp of what your weaknesses and strengths are. One fact you’ll note from the NHC Official Track Error Cumulative Distribution graph on that page is that the NHC is well aware of the size in nautical miles of their forecast track error 3-5 days out. They even remind readers of the error size in their forecast advisories.

Just thinking about that fifth point, if you know your forecast track can be off by 400 miles or more for the hurricane’s possible location 5 days out, why would you stick with that forecast when it changes the next day in most of the models? In other words, if you know yesterday’s long-range forecast had a high probability for being wrong, wouldn’t you adjust it for what you’re seeing today?

Hindsight can be 20/20 as they say, but it’s unfair to Monday morning armchair quarterback a forecast track for a storm as huge as Irma. Rest assured that meteorologists are probably already looking at the above information and then some, trying to understand whether last Tuesday morning’s forecast was dead-on because it was good or if it was just an interesting coincidence.

Weather Blog

Hurricanes bring the unimaginable to life

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Last night was the 21st anniversary of Hurricane Fran hitting North Carolina. If you lived here, I probably don’t need to remind you. The devastation in Raleigh and Wake Forest made the area look like a war zone. Large oak trees were down with root balls rising into the air, blocking views of the houses they once shaded. Many people lost trees to the relentless wind and rain, and many lost homes to fallen trees. Everyone lost power, some for over a week. People had cookouts to feed their families and neighbors and in order to eat perishable food before it spoiled.

Fran's track

The track of Hurricane Fran as shown on a map courtesy of the National Weather Service.

The National Weather Service Raleigh Office published an excellent summary of Hurricane Fran’s lifespan and impacts. Within it, there is a radar loop from the time Fran came ashore on our southern beaches to the time she impacted Wake County, doing $900 million in damage to our one county alone! For some readers looking at the page, it may be the first time they’ve seen the radar images, especially since the area was without power during the storm. The maps at the bottom of the summary show a bullseye with 10 plus inches of rain over Wake County and maximum wind gusts of 50 to 90 miles per hour, depending on which side of the county you resided.

If you experienced Fran or any other tropical system like her, you have an idea of the kind of devastation a hurricane can bring. Remember those howling winds and the rain pelting your roof and windows for hours on end, the brief and eerie silence as the eye passed over, and then more wind and rain that seemed to go on forever. Now imagine living through a Category 5 storm like Hurricane Irma. This morning she hit the island of St. Maarten, and her destruction was caught on camera.

I literally couldn’t imagine winds over 120 miles per hour. I’m not talking about a gust, or a tornado that hits briefly and then dissipates. I’m talking about non-stop wind consistently beating on your structures and then add rain and storm surge – damage on top of damage. Can you imagine it? Thanks to modern technology, you don’t have to. Beach cameras in the islands are bringing the unimaginable to our electronic screens while we sit and wait and wonder if Irma will affect North Carolina.

If she does – and she likely will in some way early next week – she won’t have nearly the power she did this morning as a Category 5. That doesn’t mean we should let our guard down. We saw with Fran and Floyd and Matthew that it doesn’t take a major hurricane to do major damage even this far inland.

Our best bet is to be prepared, but don’t panic.

Weather Blog

Playing whac-a-mole with click-bait

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Over the weekend, a story went viral calling for a change in hurricane categories to include a Category 6. Meteorologists recognized it for the click-bait it was, but many non-meteorologists did not and shared it – much to our chagrin.  The story was written by a politician and published on a website that appeals to preppers and conspiracy theorists, which should be an automatic red flag to any reader with critical thinking skills. I’m not going to name the story, the website, or the writer here because I don’t want to encourage anyone to waste their time reading it.

Trying to squash stories full of misinformation and unlikely worst-case scenarios is meteorologists’ version of the game whac-a-mole. It’s frustrating, and I doubt we’ll ever truly win.

The reason this particular story was so off-base and unhelpful was simply that it was written by someone who (I can only assume) didn’t even do basic research on what a Category 5 storm is on the Saffir-Simpson Hurricane Wind Scale. I will even admit that I had to refresh my own memory this morning after seeing red when realizing how viral that post had become.

Irma map

Hurricane Irma is a Category 5 storm as of this morning, September 5, 2017.

The description of Category 5 storm winds includes the wording “157 mph or higher,” which means there is no reason to change the scale. If we do see winds higher than ever seen before, it will still be called a Category 5. If meteorologists decide to change the scale at some point in the future, they will likely shift the scale’s wind speeds similarly to the way the tornado categories changed by going from the Fujita Scale to the Enhanced-Fujita Scale. If that decision is ever made, it will be made by the expert scientists, not politicians.

Part of the reason Category 5 storms don’t usually strike the continental US while sustaining that strength is they typically hit slightly cooler waters and more wind shear after crossing the Gulf Stream and other warm ocean currents, which weakens them. Moving over land such as the islands in the Caribbean also weakens storms. Still, strong storms such as Camille and Gilbert do occasionally make landfall while maintaining status as a Category 5. It happens, but it’s rare.

Category 5 storms in general aren’t as unusual as one might think, though. One of the problems with being human is we tend to have short memories about things like storm strength.  If you look at the National Hurricane Center’s “Hurricanes in History” page, and just do a search of the term “category 5,” you’ll see just how many of those storms summarized on that page actually reached that status and then weakened before hitting the continental U.S. (7) versus how many made landfall while sustaining Category 5 status (3).

One of the false points made in the click-bait article was that Irma strengthened faster than meteorologists expected. This was untrue. Several of the models showed Irma bombing out as soon as she reached warm waters and ideal conditions. Again, this happens. We wouldn’t already have the phrase “bombing out” if it didn’t. A storm is said to “bomb out” when it strengthens rapidly, showing a large, fast drop in barometric pressure.

Another point that article claimed is that a storm of Irma’s potential strength would wipe cities off the map. The potential for that kind of devastation should go without saying for any major hurricane. Residents of North Carolina in the 1990s will tell you about the eastern N.C. town of Princeville, which was literally destroyed by Hurricane Floyd’s flooding. By the way, Floyd peaked at Category 4.

If you follow other meteorologists on social media, I’m sure you’ve seen many of them trying to squelch false weather stories, outlandish claims, worst-case doctored forecast maps, etc. I think I can speak for all of us when I say we’re frustrated with the rampant sharing of dis- and misinformation about the weather.

Before you share a story that seems too good or too bad to be true or is from a source that seems suspect, please take a moment to think critically about it, even research it if you have time. If you aren’t sure of its validity, just don’t share it. Don’t be part of the problem, please!

Weather Blog

If…

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“If” is the biggest word in the English language, or so I’ve been told.

If I controlled the weather, we would still have tropical cyclones because they are an important part of the global system that encompasses weather, climate, ecology, and environment. Often, years without tropical systems end in drought. However, if I controlled the weather, Harvey would not have played out this way.

Harvey's forecast track

The National Hurricane Center’s forecast track for what’s left of Tropical Storm Harvey.

If I controlled urban development, we would not have cities built on barrier islands, or in flood zones, or in areas prone to annual wildfires… or in California now that I think of it. Yep. California would be one gigantic National Park. No urban centers allowed.

If I controlled human behavior, everyone would be patient, kind, and logical. People would understand just how complicated the world is and would find ways to reason out the best possible solutions to our problems without making more of a mess despite (or by way of) the best of intentions.

Are you rolling your eyes yet? I am.

If is a great playground for the mind, but if does not deal well with reality in this case.

Harvey is bad. Urban development in places like Houston exacerbates flooding potential. When things get bad, human emotions get riled, and many people have their own way of dealing with bad situations – not all of which are inherently bad themselves, but many of which are less than constructive.

I could write about how Harvey is breaking official records, but we’re still awaiting verified, quality-assured data. I could write about how my heart breaks for those affected by Harvey, but if you’re as human as the next guy, your heart is right there with mine. I could write about how to make charitable donations to help with recovery, but I know the rest of the media has that covered. (I chose the Red Cross, personally.)

Instead, I’ll just say that when the waters recede, the national media leaves, and those people who can return home to start picking up the pieces do… that’s when we will have time to head back to the playground called If and see what imagination, ingenuity, and logic can do to help us mitigate future potential disasters like this one.

Weather Blog

The eclipse created smiles.

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If you spent any time on social media after the eclipse yesterday, you probably saw as many mixed reviews as I did, especially from those who witnessed it locally and did not travel to the path of totality. I noted descriptions from “beautiful” and “awe-inspiring” to “cool” and “that was it?” For many, it was a great experience. For others, it wasn’t worth the hype.

eclipse on paper

Amy Yinger rigged binoculars to capture the eclipse.

The experience here at the office in Wake Forest was pleasant and unsurprising. I understood that we would not experience totality and therefore not experience a dip into total darkness. Instead, the light grew dusky for about 20 minutes. The temperature dropped measurably, but not over-dramatically. My coworkers and I enjoyed a little time outside on the grassy area near Town Hall watching the projection of the eclipse change by the moment as it peaked.

What I noticed most were the smiles the eclipse created. From those beside me to friends posting on Facebook and from those staring into boxes and paper plates to those wearing their NASA-approved eclipse glasses with eyes raised to the sky, everyone was smiling. I think that, my friends, made the whole thing worth it to me despite my burnout on the hype, about which I wrote yesterday.

If you follow this hyperlink, you can take a look at some of the photos I took with my little old cell-phone yesterday, and you’ll see a few of the smiles to which I’m referring.

Weather Blog

I’m not an astronomer, and I don’t play one online.

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Eclipse mania has officially driven me mad. Well, maybe not truly mad, but I’m tired of the hype.

Is it a total eclipse a rare event? Somewhat, but not as rare as you might think. According to Space.com, “… in any calendar year, there are at least two solar and two lunar eclipses visible somewhere on Earth. The maximum number possible in a single year is seven — a mix of the two kinds. This year, we’ll have four.” Today’s eclipse is only truly rare in that the narrow swath of visibility crosses the entire continental United States.

Don’t misunderstand me. I get why people are excited. I was excited about it back in February when I first learned of it. I even considered finding a way to go to Charleston with a friend to witness it there. Since then, though, the buildup on the news and on social media has been over-abundant and overwhelming.

astronomer meme

Meteorologist Niki Morock made this meme, inspired by the suggestion of a coworker to make a new eclipse meme.

Television broadcast meteorologists have positioned themselves (rightly so) as station scientists, and are depended upon to explain all things related to earth, atmosphere, and space as if they are total experts. A few may have taken astronomy classes as optional choices in school, but astronomy is not required to earn an atmospheric science/meteorology degree. I myself never took an astronomy course, and I will be the first to admit that I don’t know much more about it than I do volcanology – which isn’t all that much.

The information I have posted about the eclipse came from Nasa.gov and Space.com because those sites are teaming with experts. I trust them to have reliable and useful information regarding the eclipse. My guess is that most broadcast meteorologists are using those and other similar websites as resources to answer questions and make predictions about today’s eclipse.

When I have been asked questions that should be answered by an astronomer, I have directed people to those sites. I’m not even going to pretend to know more than I do. Can I learn more? Yes, and I have over the last few months. Do I feel like I’m an expert now? Not at all. Reading a few pages on space-related websites doesn’t replace earning a science degree in a specialized field. I’m no more of an astronomer today than you are a meteorologist because you watch the Weather Channel every morning.

I will be out this afternoon taking in the effects of the eclipse as it pertains to temperature and the reactions of living things because even at 90-95% totality, it will be interesting to experience. Maybe I will write about my observations and we can compare notes tomorrow. I know one thing for sure, I’ll be happier tomorrow knowing that I can avoid being asked astronomy-related questions… at least until the next time.

Weather Blog

Two weeks is too soon: long-range forecast vs. reality

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Hurricane Gert is currently southeast of the North Carolina coast (at 9:00 am on Tuesday, August 15, 2017). She is a Category 1 hurricane with sustained winds at 75 miles per hour. Expect her to turn toward the northeast today and strengthen a little before she becomes a post-tropical storm in the North Atlantic later this week. At this point, the only effect our coast will feel will be from swells and rip tides. As a friend of mine put it, “She’s a good surfing storm.”

satellite image

August 15, 2017 satellite image of Hurricane Gert off the southeastern U.S. coast.

What a difference two weeks has made! When I first started watching the forecast models and how they were handling the would-be tropical system, the GFS showed Gert slamming into the coast of Georgia at about 2 AM Thursday.  According to the National Hurricane Center’s 5 AM advisory today, by early Thursday morning, Gert should be far from land in the North Atlantic – still a hurricane, but not a threat to anything but transportation lanes on and over the ocean.

So, what did I learn or confirm from this little exercise?

A forecast two weeks in advance may have some hint of what is to come, but the details are far from exact. On Thursday, there will be a hurricane in the Atlantic, but the positioning, strength, and direction were all wrong. While I suspected as much, I wanted to prove it to myself and my readers with documentation.

Hurricanes aren’t the only events people ask about, tempting meteorologists to forecast several weeks in advance. The weather for the solar eclipse on Monday is another example. I’ve been asked how the weather will be on that day at certain locations since last month. It was difficult to hold my snarky replies in check. Anyone forecasting weather a month in advance is either looking at climatology, or she’s rolling the dice, throwing a dart, or guessing randomly. There is a chance to be right, but more than likely, she won’t be. So, I didn’t even try it, especially for an event inspiring such anticipation.

I have a sweet cousin getting married in upstate New York on August 26. Sure, I looked at what the models are predicting this morning while I was making the Wake Forest and Butner-Creedmoor forecasts. I didn’t like what I saw. Her outside wedding could end up wet. Of course, I could tell you that part anyway because that is the nature of planning an outdoor ceremony. Will I urge her to move it inside based on a long-range forecast model 12 days in advance? Heck no! I’m not even going to mention the possibility of another hurricane being just off the east coast that weekend.

Hopefully, she doesn’t read this blog. (Wink. Wink.)

NHC forecast

The 5 AM, August 15, 2017, National Hurricane Center forecast track for Hurricane Gert.

Weather Blog

Where’s that storm?

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Last Thursday, I wrote about the potential problems with mentioning possible tropical storms the minute they show up on a computer forecast model. I promised to look at a specific date and time on the GFS model every morning until that date – 06Z Thursday, August 17, 2017.  The following day, I noticed several meteorologists mentioning a potential tropical storm the week of August 13-19 on social media.

By Monday, my point was proven. The model that I was watching no longer showed any hint of a storm anywhere near the Atlantic Coast on August 17. I had to look days in advance to find a shadow of what the forecast storm had been.

This morning, the GFS had dropped it altogether. Ironically, a few of the other models have picked up on a potential, weak storm that could travel up the coast at the beginning of the week. In fact, I took a few screenshots of 0Z Monday, August 14.

Comparisons between what I have seen today and last week:

GFS forecast precipitable water

The GFS model shows available moisture for 0Z, Monday, August 14. The tropical system is barely a shadow of what the model was predicing last Thursday.

Last week, the GFS had the storm slamming the coast of Georgia. Today, the ECMWF and CMC models have it staying well out to sea.

Last week, the GFS showed a strong low pressure system with a pretty high amount of moisture available to it. Today, the ECMWF and CMC models show a weak system with about the same amount of available moisture that the east coast of South Carolina is experiencing today – typical summertime moisture for that coast.

Last week, the GFS showed winds around the center of circulation around 75 miles per hour. Today, the ECMWF and CMC models show winds around 20 miles per hour.

It is still possible that the system develops into something worth talking about in the next few days. The National Hurricane Center is keeping an eye on it. My point here is that a great deal can change in just a week or two when it comes to long-range weather forecasting. The answer to my question of “How far out is too far out?” may not be cut and dry, but in this case, we can safely say that two weeks is still too far out for any real accuracy, at least with the technology we have today.

 

Note: 0Z is midnight Zulu time, which translates to 8:00 PM Sunday evening in Eastern Time.

 

For those who love weather maps, here are some of the screenshots I have taken for this little experiment:

forecast from 8/3/17

The GFS forecast for 06Z, August 17, 2017, as seen on Thursday, August 3.

GFS on 8/4/17

The GFS forecast for 06Z, August 17, 2017, as seen on Friday, August 4.

GFS on 8/7/17

The GFS forecast for 06Z, August 17, 2017, as seen on Monday, August 7.

CMC 8/9/17

On August 9, the CMC model shows a storm well off the US coast at 0Z, Monday, August 14, 2017.

ECMWF model on 8/9/17

On August 9, the ECMWF model shows a storm well off the US coast at 0Z, Monday, August 14, 2017.

On August 9, the GFS model for 0Z, Monday, August 14th, shows just a week disturbance off the coast of Florida. There was nothing notable about the forecast for 06Z, August 17, with regards to the tropics at this point.

NHC map

The National Hurricane Center is watching an area of disorganized storms that may become a tropical storm early next week.

Weather Blog

How far out is too far out?

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This morning, while making the forecast for the next 5 days, I saw an interesting scenario on the GFS long-range model. My first thought was “That looks impressive!” Then I wondered how many young, reckless, let-me-just-make-a-name-for-myself meteorologists were going to flood social networks like Facebook and Twitter with screaming headlines about a terrible hurricane hitting the southeastern coast exactly two weeks from today.

Yep. There’s a tropical system striking Georgia in that model.

GFS model forecast map

The GFS forecast model shows a tropical system hitting the coast of Georgia on August 17, 2017.

I’m not mentioning it here for click bait or trying to be the first to talk about it. I mention it because it’s there and it will be interesting to watch how the model develops and changes the forecast from day to day. This morning, I took a screenshot of what I saw two weeks out for that exact time and date. I will continue to take screenshots between now and 06Z Thursday, August 17, 2017, of what the model is predicting for that exact time. In two weeks, I will post them, and we will see how things have truly developed from today through this morning ’s projected day of landfall.

I will give you a hint. I’m not expecting it to happen the way the GFS is predicting today.

I’ve written before about how the accuracy of the numerical weather prediction models decreases the farther out you go. Factors that the models aren’t even aware of can affect the forecast just a week out, even more so two weeks out. It would be irresponsible to say that we’ll be dealing with a hurricane two weeks from today knowing what I know.

Or would it?

Would anyone on the coast be more likely to prepare if they had two-weeks warning? Or are they savvy enough about the models to think they should ignore it for at least another twelve days?

My guess is that they would wait to see how it progresses because they live in an hurricane prone area and are used to forecast tracks changing. On the other hand, the not-as-savvy people inland who are considering a vacation at the beach that week may panic and start worrying about whether they should have bought trip insurance.

Until the computer models are more consistent with long-range forecast accuracy, anything more than a passing mention of a potential tropical system somewhere on the southeastern coast of the United States is imprudent. Still, I’m going to do my little screenshot experiment to see how this plays out. I’ll let you know.