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Florence vs. Fran: a comparison

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With Hurricane Florence likely to make landfall somewhere on the coast of South Carolina, North Carolina or Virginia, people are raiding the grocery stores for water and non-perishable foods. The official National Hurricane Center forecast track as of 11:00 this morning shows the center of the cone of uncertainty near Wilmington and Florence being a major hurricane – category 3 or higher – at landfall. Many who have lived in this area for years are starting to compare the forecast track to Hurricane Fran, and with good reason, and that may be why locals are taking this one so seriously.

There is another similarity to Fran that could be cause for concern: the soil saturation level. A friend at the Southeast Regional Climate Center shared some data with me this morning comparing the soil saturation at the end of August this year versus in the same time in 1996 a few days before Fran hit. (See the charts below.)

Since that data is for the end of August, and we are 10 days into September, I also looked at the calculated soil moisture as of today from the Climate Prediction Center, and it appears the eastern half of the country is still on the wet side.

Saturated soil plus heavy rain and high winds are what brought the oaks down across Raleigh during Fran. It’s definitely a concern for those of us with yards full of trees, especially oak trees.

Heavy rain is a real possibility with weather models calling for anything from one to four feet. Where the highest totals will happen is still up in the air because each model is putting the bullseye in a different part of the state. The Weather Prediction Center has the bulk of the rain falling in eastern NC as of this morning, but that may change tomorrow.

As the date and time of landfall gets closer, the models will have a better handle on where that will be, how strong the winds will be, and where the bulk of the rain will fall. Until then, don’t panic, and especially don’t panic over maps that people on social media are sharing that only show what one model out of dozens says might happen. Chances are, it’s not accurate. Follow the updates from the National Hurricane Center and our local National Weather Service office.

Panic won’t help. Preparation will.

Personally, I’ve decided to do what I can to mitigate possibly flooding of my crawl space, make sure anything that might blow away is secured, and make sure I’m stocked up on supplies. The rest is up to a higher power. It’s easy to get wrapped up in worry over my trees coming down, roof damage, or a leaky shed, but there’s not much I can do to stop the rain and wind from coming despite what powers people seem to think meteorologists have over the weather.

We’re all in the same boat here…

I hope I don’t need a boat.

RDU rainfall comparisons

A comparison of the precipitation accumulations for the summer of 1996, 2018, and the 30 year average at RDU.

 

comparison at NCSU

A comparison of the precipitation accumulations for the summer of 1996, 2018, and the 30 year average at the NCSU coop reporting station.

CPC soil moisture

The Climate Prediction Center’s map of Calculated Soil Moisture for September 9, 2018.

 

 

WPC QPF

The Weather Prediction Center’s forecast total rainfall for Monday, September 10, 2018 through Monday, September 17, 2018.

Weather Blog

A Florence landfall is a possibility

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As “late next week” starts to come within range of increased model accuracy for tropical storm forecast tracks, more of those models are bringing Florence – at this writing a tropical storm – farther west. There’s still no guarantee she’ll take any one particular path and climatology is technically against her making landfall, but it’s hard to ignore the potential now.

There are a few points I really want to make with this post:

  1. Just because no hurricane on record started where Florence started and hit the US mainland as major hurricane doesn’t mean that it has never happened. Accurate keeping of storm track records is a relatively recent activity, especially when you factor in satellite records. To the same point, it also doesn’t mean that it can’t ever happen. As the saying goes, there’s a first time for everything!

    spaghetti models

    Tropicaltidbits.com’s map of the spaghetti models – multiple numerical weather model potential forecast tracks for Florence

  2. It’s still too early to tell. For the most part, hurricane track forecasting is not very accurate more than five days out, which is why the National Hurricane Center’s official track only shows the next five days. It’s also the reason the cone of uncertainty on that track is widest on the fifth day. Often, the storm’s path will fall somewhere within that cone, but if you watch the updates religiously like we weather geeks do, you’ll notice even the cone moves with each new model run.
  3. Despite potential landfall still being too far out to say for certain if it will happen, it is a good time to go ahead and prepare, especially if you live on or have property on the coast. It only takes one storm to devastate an area, and even if Florence is not that storm, there are two more potential tropical storms lining up behind her off the coast of Africa. And it’s definitely too early to tell where they will go.

We are currently in the climatological peak of hurricane season for the north Atlantic, and the ocean’s temperatures have become much more conducive to storm production in recent weeks. If you haven’t already prepared, now is the time.

NHC map

The National Hurricane Center‘s forecast map for Florence as of 5am, September 7, 2018

Weather Blog

How we count matters

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Once upon a time, I took a statistics class in college. On the first day, the professor told us a simple truth we needed to understand before we started down the road of probabilities, bell curves, and standard deviations. He told us that numbers can be made to say whatever we wanted them to say. At that time, I was a mass communication major whose favorite class was Criticism of the Information Media, and the idea hit home quickly. That class taught me to think critically about the statistics we see in the news and to ask how they are calculated. Most people don’t consider it too deeply, but how we count matters.

The past few weeks have brought that point to the forefront with reports of revisions to the death toll from Hurricane Maria in Puerto Rico. This week’s revision brought the number to about 3,000, but why did the number jump so high from the initial, official report of 65? In Miami, the NBC station’s Chief Meteorologist, John Morales, published a blog post this week that explains well how they arrived at those numbers. Basically, he makes the point that what is being counted and how it’s being counted differs from report to report.

Maria Radar

From the National Hurricane Center’s summary of Hurricane Maria: San Juan WSR
-88D radar image of Hurricane Maria
at 0950 UTC 20 September,
just before landfall in Puerto Rico, showing
the more dominant outer eyewall. This was the last image fro
m the radar before it was destroyed.

The initial, official report was of deaths directly related to Hurricane Maria’s wind, rain, and flooding. The following reports with numbers in the thousands were those of “excessive deaths” that could possibly be linked to the after-effects of Maria’s damage in the months following her landfall, and each of those follow-up reports counted things differently. Read Morales’ blog for more information.

To quote Peter Griffin on “Family Guy,” “what really grinds my gears” about the revised death toll studies more than anything is how most media outlets are reporting them – with a headline and a sentence or two and little-to-no explanation of what the numbers truly mean. They are being reported as hard fact and not best estimates of deaths indirectly caused by the storm.

There are other weather-related numbers that get tossed about regularly in news reports and taken at face value, which can often be misleading. Take for example, stating local temperature records such as the coldest or hottest high temperature for the date. The additional information needed to put those records into context includes how long records have been kept for that specific location, has the thermometer always been accurate and reliable and sited in the appropriate spot for the purpose, or has it been moved and/or replaced? Are there quality control processes for the data in place? If so, what are they? Are there historical gaps in the data?

Granted, when a reporter only has three seconds to mention a factoid in passing as he transitions to a larger story, it’s difficult to include all that information. For that reason, we need to be willing to ask those questions and dig a little deeper if it’s a topic that matters to us and a fact we plan to repeat at the coffee bar.

What about other superlatives like “most destructive hurricane” or “most expensive storm”? Are we considering inflation, insurance, building codes, population density? Is it fair to compare a hurricane which affects the densely populated Mid-Atlantic and New England region to a storm that hits mostly rural Florida and Georgia if both storms’ attributes were equal? More people and more expensive property may be affected in New England, but that doesn’t make the devastation in the Southeast any less real to those who suffered it.

Regular readers of this blog know that my goal in writing it is to challenge you to think about science in the news in an educated way. My personal opinions may differ from yours, and that’s fine with me as long as you’re thinking more critically about what you hear and read as a result. In this new virtual world of flashy headlines and little substance, it’s our personal responsibility to be media savvy.

Weather Blog

Hurricane Camille – a look back

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One of the strongest, most devastating hurricanes to hit the United States mainland hit 49 years ago today. Hurricane Camille blew ashore with winds estimated to be 190 to 200 mph and gusts to 220 mph or higher. Her storm surge was estimated at a whopping 24 feet, and between her arrival as a Category 5 on the Mississippi Gulf Coast and her exit off the Virginia coast, she caused 256 deaths and $1.421 billion in damage.

As an exercise in personal curiosity about how the events played out from a meteorologist’s perspective, I spent some time this morning reading all the bulletins issued by the National Hurricane Center in Miami. The dates ranged from Thursday, August 14, 1969, when the storm first formed near Grand Cayman to Friday, August 22, when the storm finally lost her identity over the northern Atlantic.

That last part was a surprise to me. As someone who was born several years after the historical hurricane and who spent some of her youth hearing about it while living in Jackson, Mississippi, I realized today there was much more to Camille than I ever knew.

I knew she had done major damage as far north as Jackson, but I didn’t know it was because her sustained winds were still estimated to be around 80 mph as her center passed about 20 miles east of the capitol. I also didn’t realize that 113 of the deaths she caused happened when her remnants passed through the mountains of West Virginia and Virginia the following Tuesday dropping up to 31 inches of rain in some spots and causing flash flooding throughout the region.

By Wednesday afternoon, she moved off the coast of Virginia and actually regained some strength with winds back up to 60 mph, but thankfully remained a shadow of her former self. She continued to cause concern for the shipping industry until she finally fell apart over the colder waters of the North Atlantic on August 22.

While reading the bulletins and advisories which were issued every two to three hours from the time of her formation to about the time her center passed through northern Mississippi, I felt the anxiety the forecasters must have felt as they tracked her progress and tried to predict where she would make landfall. In 1969, meteorologists didn’t have the powerful forecast models that we have today that can predict the potential for tropical storm formation several days before it happens. Storm track and storm surge prediction tools left a lot to be desired.

As late as 1:00 PM on the day Camille made landfall, the forecasters at the National Hurricane Center were predicting a storm surge up to 15 feet. At 3:00 PM, they issued a Special Advisory with updated information and a revised storm surge prediction up to 20 feet. The reality when she made landfall around 11:00 PM was 4 feet higher. On a low-lying coastal plane, four additional feet can make a big difference in how far inland surface-based (as opposed to rainfall-based) flood waters reach.

I can only imagine having less than three days’ notice that a hurricane may hit your country’s coastline, and worse, having less than a day’s notice that your specific area really needs to evacuate before it’s too late. The anxiety that must have been felt by meteorologists, local authorities, and the general public by that Sunday morning had to be unbelievable.

flattened buildings

Image courtesy of NOAA: some of the absolute devastation Hurricane Camille caused on the Mississippi Gulf Coast

The images of the destruction Camille left in her path tell the story of how she took so many lives. High winds, incredibly high storm surge and about ten inches of rain on the Mississippi coast flattened some areas and left others looking like a war zone. While we can’t stop storms like Camille from happening, we can be – and are – much better prepared than they were back then. Our current models aren’t perfect, but with the ability to better predict the track, winds, and storm surge a hurricane may have, our emergency managers and state and local authorities usually have much better lead time to issue evacuation advisories and orders.  As long as the people affected take those notices seriously, they should lead to better protection of life and property, which is the ultimate goal of all meteorologists.

Weather Blog

Radar has its limitations and meteorologists can’t be everywhere.

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Yesterday on my Facebook page, I posted about the limitation of just looking at the radar to see when it will rain. I had gotten stuck behind three farm tractors for about ten miles on a country road on my way home from work and had time to really look at the sky while I was driving. It’s something I don’t really do while going 55 mph on a two-lane road, but I will do it while going well below 20 mph. I was watching storms grow to the south of the Triangle and noticed one cumulonimbus cloud had developed a nice anvil top by the time I arrived home. I parked in my driveway, looked at the radar and saw nothing.

The situation inspired me to post a reminder that the radar only shows you where the rain is at that moment – or at least, within a 6 minutes span of time containing that moment. The radar can’t show you where a storm cloud has developed but has not started precipitating.

Fast-forward to my drive into work this morning when I heard a news report on the radio about the storm on Lake Norman yesterday. Twenty-six people had to be pulled from the water after a “sudden storm” capsized their boats. Thankfully, all survived.

Now, I am sorry they experienced a dangerous situation on the water, but I have a problem with phrases such as “sudden storm” and “it hit without warning,” when used to explain weather-related mishaps. I need to remind myself as I feel my hackles rise that not everyone studies the sky the way weather geeks do. In fact, it often surprises me how the people around me respond to my reactions to what I see.

Instead of being defensive of the great job that meteorologists do in trying to prepare the public for the possibility of storms, which I admit is my normal reaction, I’ll take this moment to provide a little basic weather education. Let’s face it, if more people understood what they were seeing when they looked at the sky, we might have fewer news reports of capsized boats and lightning casualties.

First, I’d like everyone to take a moment to accept that no storm just materializes fully formed. It’s science, not magic. Every storm, whether severe or not, goes through the same basic life cycle stages. They all start as cumulus clouds and are created by warm, moist air rising from the earth’s surface.

With enough energy, those puffy clouds grow taller and become towering cumulus clouds. Around here, the tall, thin ones are sometimes referred to as “turkey towers.” These clouds consist mostly of updraft – that warm, moist air rising from the surface. The edges of the storm at this stage have a cauliflower look to them.

As the storm cell matures, it produces precipitation because what goes up, must come down. With the rain – and possibly hail – cooler air from the top of the cloud also drops from the storm. In a non-severe storm, you feel it as the cool breeze coming out of the cell. In a severe storm, that air can rush out at over 100 mph! The damage it can cause is worse that a small, weak tornado. A mature storm may have what we call an anvil top – a flattening out – if it’s powerful enough for the top of it to reach the tropopause.

At some point, the amount of air flowing out of the storm exceeds the amount of air flowing into the storm. In fact, the outflow can cut off the inflow. At that point the storm is dissipating, or weakening, and will soon die. Dying storms have softer edges as if an artist took a brush and blurred them a little.

For those who can’t quite visualize the lifecycle from my description, take a look at the graphic below from weather.gov, NOAA’s National Weather Service website.

Now that you can identify a threatening storm – meaning one that is reaching the mature stage, you can consider other factors in deciding what action to take.

  • If you hear thunder, seek shelter. As the saying goes, “If thunder roars, go indoors.” If you are close enough to hear thunder, you are close enough to be struck by lightning.
  • If the storm is moving toward you but you don’t hear thunder, seek shelter. There has to be a first lightning strike somewhere, and it might be too close for comfort.
  • If the storm is moving away from you and you don’t hear thunder, you could still take the better-safe-than-sorry approach and head inside for a bit. The other option is to appreciate the beauty and energy of it while also putting your head on a swivel to look for signs of other storms in the area. Sometimes a storm is truly isolated – a single pop-up storm. More often, there is a forcing mechanism that is providing the energy for multiple storms – such as a leeside trough, a cold front, or a sea breeze. If you see one storm, be aware that there may be more forming.

I’m not concerned for my job security in sharing this information. Meteorologists can’t be everywhere, and we need an educated public in order to achieve our goal of protection of life and property from the weather. So, please, share this information with others. The more people who have a situational awareness of the weather and can identify a potential threat, the fewer news stories we’ll have with disastrous endings.

lifecycle

Photographic examples of the three basic stages of a thunderstorm from weather.gov

Weather Blog

A weather girl’s garden

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Put a dozen strangers in a room. Add three more just in case you need them. Tell them they can’t talk about the reason they are there and wait. Of course, the first topic of conversation is the weather followed by jobs, hobbies, and pets.

You might have a clue what I’ve been up to for part of the last month. I served as an alternate juror on a local criminal case. It was definitely an interesting and educational experience. While I don’t wish a long trial on anyone, I do think it’s one of those things in life that everyone should do. You learn much about how our court system really works. Believe me. It’s not like you see on TV. In fact, after our first week of service, one of my fellow jurors quipped that he used to love Perry Mason, but no more.

It’s also stressful for those of us who have full-time jobs and real life to balance while serving. Personally, I made the forecast for frontporchweather.com and our community newspapers before going to court. Then after the long commute back home, I attempted to get additional work done, have dinner, tend my garden, and entertain my cat. It was a busy few weeks.

I share this because my regular readers might have wondered why I stopped writing for a while. Now that I’ve had a chance to settle back into work and I feel like there’s time again, I can return to my regular routine of posting at least weekly.

A weather girl’s garden

I wrote earlier this year about my excitement over planting my first garden. Let me tell you how much more I appreciate farmers after this first few months. I mean I was grateful for their work initially, but after fretting over my timing, my watering, the heat, and the bugs, I feel like I have a better idea of what their lives entail, but on a grander scale than mine, of course.

garden

The author’s squash and zucchini plants along with her black-eyed Susans

I started planting later than expected because the cold weather lasted later into the spring than it usually does here. April was both cooler and wetter than normal. Between the weather and my schedule, the calendar said May before I finally cleared the weeds and planted the vegetables. I worried needlessly that I had started too late, and I nearly did a cartwheel when I saw sprouts just a week later.

According to the North Carolina Climate Office, the next month was our wettest May on record dating back to 1895. It was also one of our warmest as a persistent pattern revolved around a Bermuda high just off our coast for much of the month. The rain helped the plants grow despite my fears that the heavy downpours might washout their new root systems.

Then June arrived. Short stretches of dry days made me grateful for my two rain barrels. By June 20, I noticed the water wasn’t coming out of them as quickly. “Oh, no,” I thought. “Now I have to worry about water, too.” Thankfully, the next day, I recorded 1.27 inches of rain in my CoCoRaHS rain gauge. (Yes, I’m an official observer now thanks to a friend’s donation of the gauge to my garden.)

Last week, I asked my neighbor what the bugs on my squash and zucchini plants were. Apparently, they are not-so-creatively named squash bugs. I only saw a few, so I didn’t worry too much. My plants were thriving. In fact, I picked my first zucchini Friday night and did a little happy dance right there in the garden!

Last night, I went out to check the plants as I do daily, and there were dozens of those darn bugs all over the place – mostly small ones. Dang it! I Googled “natural ways to kill squash bugs,” and found suggestions for manually squishing each one. Ew! I also found other options – castile soap and water, neem oil, and store-bought insecticidal soap. I tried the castile soap and water solution but saw no immediate effect… except for maybe shinier squash bugs.

I rushed to the home improvement store to check out the neem oil with the highest online rating. Despite it being called “natural,” there is a warning on the label that says not to allow it to seep into storm water runoff. As many times as I have written over the years about protecting our water resources by being cautious about what we allow in our storm drains and streams, I couldn’t possibly buy that product. So, I bought the insecticidal soap, took it home, and sprayed them with that, too.

I guess I’ll know this evening if it helped. If not, I’ll put on some gloves and squash some bugs.

CoCoRaHS report

The author’s daily rainfall reports from her CoCoRaHS rain gauge

Despite the unexpected amount of anxiety over every new potential issue, I am enjoying gardening. (Did I mention the fire ants?) It was the impetus I needed to become an official CoCoRaHS observer. Since signing up, I have diligently recorded my rainfall or lack thereof daily. To be able to look at the Daily Precipitation maps on the website to see how my data stacks up to others in Wake County and across the state has been neat. For example, last night, my garden only received a trace of rain, but down in Cumberland and Hoke counties, they saw two to three inches. Last Thursday, when I recorded 1.27 inches, the 24-hour total was the second most in the whole county. The geographically nearest reports to mine were only in the hundredths of inches. Those results were not much of a surprise to me since I was watching on the radar little cell that dumped all that rain in just about an hour.

By the way, northeastern Wake County could use a few more observers. If you’re interested in helping scientists track rainfall, you can learn more at cocorahs.org.

Penny

The author’s cat, Penny, overseeing her work in the garden from her favorite perch

Weather Blog

Wind roses

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I love when friends and readers ask me questions I’ve never been asked before, especially when I don’t know the answer. It’s a learning opportunity! On Sunday, a friend asked how she could find out the seasonal wind direction for some property she is purchasing and planning to turn into a farm. Her goal is to be sure the barn isn’t upwind of the bedroom. Smart thinking!

While I doubted the town nearby had weather records, I knew there must be some data out there I could find to give her a good approximation. So, I asked a climatologist friend where I should look. She suggested looking at the North Carolina Climate Office’s wind rose tool.

The climate office’s website defines a wind rose as “a graphical tool used to show wind speed and wind direction for a particular location over a specified period of time.” The tool allows you to choose from a multitude of stations in six states plus Puerto Rico with hourly wind measurements.

I could tell it would prove a useful tool in the future, but not in this case. The farm in question is in southern Michigan – not in one of the six states covered. I looked up that state’s climate office website, and it didn’t prove nearly as user friendly as ours. So, I decided to take a different route and use the information provided by her local National Weather Service office.

Grand Rapids, Michigan, issues a climatological report annually for some of it’s official reporting sites. Battle Creek was the closest to the farm. I looked at the data for 2017 and 2016, and the info was pretty consistent with the average direction between the two years being just six degrees apart. In case you’re wondering, those degrees refer to the 360 degrees of direction on a compass with zero or 360 degrees being north and 180 degrees being south.

Meteorologists usually refer to the direction from which the wind is coming. A wind direction of 241 degrees means that the wind is coming from the west-southwest and blowing toward the east-northeast. In this case, we are considering the average wind direction over the course of the year, and without a wind rose to give more detail, there are some assumptions being made. We’re assuming over the long term, she’ll see the wind coming from that general direction. One thing to keep in mind with averages though, is that sometimes it takes extremes to get that average.

Cape Hatteras is a good case in point for wind extremes while Raleigh-Durham International Airport is an example of the typical direction being closer to average. Cape Hatteras has greater exposure to tropical cyclones and nor’easters and diurnal wind oscillations – meaning sea breezes and land breezes. With the exception of the occasional tropical system reaching inland, RDU’s winds tend to be generated by land-based weather systems and its piedmont geography. You can look at the wind roses for each location to see the similarities and differences.

By sharing this information, I hope to give you the ability to do your own research using recorded observational data and tools your tax dollars are backing. This is publicly-supported science at work!

Cape Hatteras wind rose

Cape Hatteras, NC, wind rose

 

RDU wind rose

RDU International Airport wind rose

Weather Blog

Is that word real, or is it marketing?

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There’s a reason I don’t read comments on social media or news posts if I can help it. They usually annoy me by reminding me just how ignorant, cynical, or mean people can be. I find it best to preserve my own relatively optimistic view of humanity by avoiding them. However, sometimes I can’t help it because Facebook highlights a comment on a post I’m reading and my own need to read gets in my way.

Today, I saw one in response to a post about the macroburst that hit New England on Tuesday, May 15, by WeatherNation on Facebook. It said, “Oh great another made-up stupid name to a storm!” In response, I posted the link to the definition of a macroburst on the American Meteorological Society’s glossary page – proof that WeatherNation did not just make up the word.

After a few moments of thought, I decided that I couldn’t blame the commenter for thinking that the word was invented for the story. It’s not like we use it very often, and it wouldn’t be the first time a media outlet invented a word or phrase for an attention-grabbing headline.

Let’s face it. Media outlets – even those based on scientific news – do not help their own waning perceived credibility by creating buzzwords, naming winter storms, and hyping the potential for disasters long before there is reasonable evidence to believe the disaster will actually occur. At this point, readers have every reason to be skeptical when they see a new term used in a headline.

Conversations among meteorologists happen pretty regularly on and offline about whether we are helping to clarify the science to the general public or serving to confuse them even more by how we present news about the weather. (I won’t even get started on the subject of the climate!) I’m of the belief that one media outlet naming winter storms when the rest of the community – including the National Weather Service – does not is more confusing to people than it is helpful. I also think that if we introduce a new weather term like “macroburst,” we need to define it as WeatherNation did and explain that it is in fact defined in a resource such as the AMS Glossary. Maybe then, non-scientists who report on the event would use it properly and not as the latest buzzword thrown around loosely in every headline to follow because it sounds cool or dangerous – polar vortex, anyone?

At the very least, maybe the reader will come away with a better understanding of the weather.

 

SPC map of macroburst

The Storm Prediction Center’s map of preliminary storm reports from Tuesday, May 15, 2018, shows a large number of high, straight-line wind reports (in blue) – evidence of a macroburst (or many).

Weather Blog

Snow in late March is unusual

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As a meteorologist, I hear the question “what’s up with this weird weather?” just about year-round. Most of the time, the weather isn’t so weird. In fact, it’s pretty typical of the season, but people have short memories and preconceived, Hollywood-influenced notions of normal when it comes to meteorology. That being said, if we see snow on Wednesday, well… that will be a little weird.

As of this writing (Monday afternoon), Wednesday’s chance for snow is not set in stone. One computer model keeps the temperature above 40 degrees, which means we will only see a cold rain. One has an early morning mix of snow and rain switching over to all rain as the day progresses. One has more snow than rain through the day. Without agreement in the models, confidence in the forecast is relatively low for now.

One thing is for certain: if it snows, the effects will be short lived. With above freezing temperatures leading up to the event and expected the day after, accumulation is unlikely – unless we see heavy bursts of snow. Of course, bridges and overpasses always require extra caution when frozen precipitation is possible.

So, how unusual is snow this late in the season? I used the North Carolina Climate Office’s Winter Storm Database to search for winter storms that happened after March 15 as far back as 1959. I found seven. Seven storms in late March over the last 58 years make the event abnormal, but not unheard of. Of those seven in the Triangle, three resulted in a trace of snow (2014, 2011, and 1981), one resulted in up to a half inch (2005), and three had amounts ranging from two to over seven inches (1983, 1972, and 1971).

Another question I’m often asked is whether El Nino or La Nina is causing the strange weather, so I looked at the historical records for the seven years in question to see if there seemed to be a link. I found none. Those storms happened during El Nino, La Nina, and neutral events. While there may be a link to some other cyclical phenomenon that I have not checked, a late-March storm may be one of those things that just happens occasionally.

1983 winter storm

Snowfall totals for the March 24-25, 1983 winter storm. Map courtesy of North Carolina Climate Office.

Weather Blog

NASA needs your help

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When was the first time you remember being told that those puffy little clouds on otherwise sunny days are called cumulus clouds? Do you recall the names of other types of clouds? It may be time to brush up, put your cloud knowledge to use, and in the process, help NASA.

The National Aeronautics and Space Administration: Global Learning and Observations to Benefit the Environment (NASA GLOBE) Clouds: Spring Cloud Observations Data Challenge starts Thursday, March 15, and runs through April 15.

cloudy beach

What kind of clouds are those? Is the sky completely covered by clouds? Brush up on your skills and and answer these questions for NASA. Photo credit: Niki Morock

The challenge is open to educators, students, and the general public, which means anyone can participate! The only technology required is access to the GLOBE Program’s data entry options online or the GLOBE Observer App, which is free in the App Store. The rest depends on some basic knowledge of clouds, your own eyes and an unobstructed view of the sky.

I downloaded the GLOBE Observer App today. It was free and easy to set up. You only need five to ten minutes to register and read the instructions once you are logged in. There are step-by-step directions on how to make an observation available on the GLOBE website here.

By participating as a citizen scientist, you are helping “scientists better understand satellite data of our atmosphere.” In other words, you are providing ground evidence to corroborate what the satellite appears to be seeing.

Why is it needed? Satellites see more than just clouds. For example, they can see ice and snow on the surface and smoke. Sometimes, those things look very different from clouds and sometimes they look similar. By collecting data from ground-level observers, scientists add to their understanding of how the satellite sees the clouds and the world below them. The better that understanding is, the better our now-casting and forecasting becomes. The improved knowledge will also help tweak the technology as we put more satellites into orbit.

Don’t worry if you don’t remember the difference between a cirrus cloud and a cumulonimbus cloud. There are tutorials on the GLOBE site, as well as tips and tricks for making a good cloud and sky observation. You don’t need a meteorology degree to be a cloud observer.

Personally, I will do what I can to participate, but in my day-to-day routine, most of my sky views are obstructed. I work in downtown Wake Forest and live on a wooded lot. Still, if the GLOBE Observer app alerts me that a satellite is about to fly over and I am somewhere with a good view of the sky, I will definitely submit an observation. Every little bit of additional, accurate data helps.