Quiet in the Atlantic; 94E in Eastern Pacific Not a Threat to Land

There are no tropical cyclone threat areas in the Atlantic to discuss today, and none of the reliable models for forecasting tropical cyclone genesis are predicting development over the coming five days (as I discussed in a blog post in August 2013, there are three models that have reasonable skill making forecasts of the genesis of new Atlantic tropical cyclones up to four days in advance--the European, GFS, and UKMET models.) Strong upper-level winds, associated w...<br /><a href="http://www.wunderground.com/blog/JeffMasters/comment.html?entrynum=2695">Read More</a>

June Gloom: Why does it occur and where is it this year?

One of characteristics of Northwest weather, and to a considerable degree the weather of much of the U.S. West Coast, is JUNE GLOOM.  The tendency to have day after day of low clouds, with a bit of an afternoon break on the better days.  Here in Washington, June Gloom often starts around Memorial Day and extends until roughly the July 4th weekend, after which our weather rapidly improves.  June Gloom is usually not accompanied by much rain, just persistent low clouds and temperatures reaching only the 60s.

But something unusual has happened this year:  practically no June Gloom so far!  To show this, here are the temperatures at Seattle-Tacoma Airport for the past two weeks, with normal highs and lows also indicated. Many days have been well above normal, with seven days getting to 70F or above.   The minimum temperatures have been above normal as well and there has been plenty of sun.  But why has the gloom been kept away this year?  First, some Gloom 101!
Gloom 101
Strangely enough, June Gloom is associated with high pressure building over the eastern Pacific and the associated formation of a huge area of low clouds.   To illustrate here is a satellite photo on June 4th, our last gloomish day, with massive amounts of stratus and stratocumulus over the eastern Pacific!  The offshore high pressure pushes the cool, cloudy marine air inland to the coastal mountain or the Cascades.


Here is the corresponding sea level pressure (solid lines) and lower atmospheric temperatures (colors, red is warm).  Nice high pressure system over the eastern Pacific (the East Pacific Anticyclone).


But why does high pressure produce low clouds and June Gloom?

High pressure areas like above have warm air above the surface, while the ocean surface and adjacent air remain cool.    That situation can produce a stable situation in which air does not tend to mix much in the vertical (warm, less dense air is above cooler, denser air).  High pressure generally has relatively light winds, which also lessens mixing.   So the air near the surface can be cooled and moistened by the ocean surface, without drier air mixing in from above.    And there is more!  Northerly flow forced by the high pressure causes coastal upwelling, with cold water ascending from depth.  This cool water contributes to cooling the air down to saturation--giving you fog and low clouds.

But why do things get murky in June?

In late spring, this area of high pressure moves northward and strengthens offshore of us; earlier in the season there is still lots of weather systems moving through and the high pressure is mainly to the south.   In June it is in its optimal position for the U.S. coastal zone to be enshrouded in clouds.  Also, as the interior of the continent heats up in June, the air becomes less dense and pressure falls.  Lower pressure inland encourages the Pacific air to move eastward .In July, the high shifts further north and enough air pushes southwestward across the coast to clear out most of the Northwest.  Also, as the high gets stronger, the low-level cold air shallows so much that it can be mixed out by the sun during the day.

If you plot the maximum and minimum relatively humidities at Seattle during year (see graphics from Weatherspark), you will notice a small maximum in early June in both.  A sign of June gloom meteorology.

The term June Gloom is heavily used in southern California as well, where they share the cooling impacts of the extensive low clouds over the eastern Pacific and onshore flow forced by the high offshore and low pressure associated with the heated interior  And some folks stay in June gloom nearly the whole summer, such as the unfortunately citizens of Monterey, California and the Pacific side of San Francisco.

So why have we been so nice this year?  The reason is that the East Pacific High Pressure area has been much stronger than normal, as illustrated by the following figure that shows the pressure anomaly (difference from normal) between June 1 and 6th..  The red indicates much higher pressure than normal offshore over the northern Gulf of Alaska.



Although most of us have been been quite happy with the sunny weather this year, there are some folks that have been disappointed by the lack of June Gloom.  Considering their typical hours and usual hangouts (around Forks, WA), you probably won't run into them.  Bring a silver bullet.


The Last Run

Final turns of the 2013-14 ski season
With a trough dropping temperatures just a bit and the hopes of getting one last day of continuous skiing to the car, my son and I hit Alta today for what I'm sure will be our last turns of the year.

As suggested by the photo below, we probably could have pieced together a continuous non-stop run to very near the base on the Collins side.


However, Alta was asking people not to park on the Collins lot.  It was Sunday, and we figured it couldn't hurt if we did, but being good neighbors we elected to go from Albion instead.

That was painful.  It's remarkable how much snow has melted in the past seven days.  My son was here on Monday and said skiing to the car wouldn't have been a problem.  Today, one had to skip from snow patch to snow patch in the lowest couple hundred vert.




Conditions improved above 9000 feet.  Things looked pretty grim up in the Supreme area (except perhaps Catharines), so we went up to Sugarloaf Pass.  It was a gorgeous day to be on skis and, with temperatures in the 40s, pretty comfortable.


It was really cool to start skiing in a winterscape, but look down at a summery scene in Albion Basin.


Conditions featured everything from bone rattling suncups (near the top, see above photo) to decent corn to snirty sandpaper.  We squeezed out what we could.


That's it for me.  I'm done until the powder starts to fly in the fall.

El Niño Odds Raised to 70% by NOAA, But El Niño is Actually Imminent

Today's guest blog post is by Dr. Michael Ventrice, an operational scientist for the Energy team at Weather Services International (WSI). This is a follow-up post to the ones he did on February 21 and April 4 on the progress of El Niño. Today's post is quite technical! - Jeff Masters

The June 5, 2014 El Niño update from NOAA's Climate Prediction Center gives a 70% chance that El Niño will form this summer, and an 80% by fall, but El Niño odds are high...<br /><a href="http://www.wunderground.com/blog/JeffMasters/comment.html?entrynum=2694">Read More</a>

The D-Day Weather Forecast: The Battle for Weather Data

Today is the 70th anniversary of D-Day.  It is not well known that a critical weather forecast played a crucial role in the victory of the Allies.  Specifically, the Allies had a much better forecasts had a far better forecast than the Germans.    General Eisenhower's forecast staff predicted a gap in poor weather on June 6th, while the German forecasters believed stormy weather would continue, making an invasion unlikely. Thus, German troops and their leaders were relatively unprepared as the Allies landed on Normandy's beeches.


In 1944, weather forecasting was a primitive enterprise.  There were no weather models, no weather radar, no weather satellites and no weather buoys.  Weather prediction was a subjective art and highly driven by the available observations.  And it turns out that the Allies had a huge advantage with access to far more observations upstream (to the west and northwest) of the English Channel, and this made all the difference.

Let me illustrate.  Here is a weather map for June 6th available to the Allies. Lots of observations over England, several ship reports over the Pacific, and at land stations on Ireland and Greenland (and North America as well).  The British had cracked the German Enigma code and thus they had access to weather observations over Europe.  The pressure analysis on June 6th is also shown, indicating a strong storm near Greenland and NW of England.



A map produced by the German weather service had few observations over the Atlantic and as shown below, not many over England.  They were clearly underplaying the low to the NW of England


Weather data over the Atlantic was crucial for European weather forecasting and the battle for weather data was decisively won by the Allies.  Weather observations were taken by Allied ship convoys  and aircraft enroute from North America. Most of the land areas surrounding the Atlantic were controlled by the Allies.  The Germans, desperate for upstream weather data, attempting to secure weather  information covertly sent U-boats out with automated weather stations.  In fact, the only known German military operation in North America was the secret landing and weather station erection in Labrador, Newfoundland.   Known as Weather Station Kurt, it ran on batteries for 6 months, and was not discovered until 1977 (see image of it, now in a Canadian museum)


Even more fascinating is that German weather reports were critical for the breaking of the German code system, which made use of their Enigma machine.  The allies were able to secure the German weather codes by boarding German weather trawlers and submarines, and then knowing the message could determine the workings of the German Enigma hardware.

Allied forecasters convinced Eisenhower to cancel the invasion on June 5th due to strong winds and clouds associated with that low that ended up NW of England the next day.  They believed that high pressure east of Spain would move in for much of June 6th, providing satisfactory conditions for the invasion (see map below)


An analysis of winds and clouds (shading) using a modern meteorological data assimilation system shows the conditions at 6 AM Greenwich Mean Time on June 6th:  modest westerly wind and lack of clouds on the Normandy beaches, a necessity of close air support of the invasion force.
There were many heroes on June 6, 1944 but is should be noted that meteorologists played an important role in the establishment of a successful beachhead that day.











Categories Do Not Exist

by Susan A. Jasko

Recently, the following question appeared in my Twitter feed (but not directed at me): What is the origin of the threshold for calling hail “dangerous”? Similarly, much social (and other) media attention was directed at an article that raises this question: Can the choice of name for representing a tropical storm/hurricane really influence how people perceive and assess the potential for danger brought by that storm? About one year ago, many folks in the weather enterprise were asking about why, when, and whether a winter storm should be named.  It was quite a “dust-up”!

Earlier this week, wind, rain, and large hail co-occurred causing damage to cars and buildings. On social media sites, I read exchanges among weather folk (professionals and aficionados) about what to call this co-occurrence. Thunderstorm? Derecho? Land hurricane? Into which category of weather phenomenon does the observed event fall?

But categories simply do not exist – at least not outside of human language and cognition. Categories are concepts. Human-made devices engineered to help us individually and collectively make sense of the world around us. They are tools enabling humans to parse the natural and social world in ways that create the bases for leveraging resources, organizing knowledge, and establishing relationships.

Although categories do not exist independently, categorical thinking helps us to grasp how things are alike and how they differ, how things are related or not related, how things may therefore be grouped, and how things may be judged and valued. Such is the power of human language: It not only describes the world, but also recreates the world in terms of human interest and attention. Categories do matter.

Language may well be the first form of human technology, and many scholars regard it as the first form of communication media. Although we commonly think of various objects as forms of technology, including cars, cell phones, computers, and automobiles, technology also takes the form of ideas or concepts, and in very much the same way as do the physical forms, non-physical technology transforms social, economic, political, institutional, and interpersonal relations among humans.  It creates powerful, pervasive, and transformative changes.

If you are still with me, you probably noticed that I seem to be implying something like “language creates reality” Not exactly. I do not mean it in the sense that the natural (physical world) is shaped by human thinking – at least not entirely. In some sense, the current “debate” about global warming partly hinges on a disagreement about whether or not human activity can in fact alter global processes. That is, the point centers on a question about to what extent human technology and engineering can change or recreate the world. But this is not where my concern resides for present purposes, and I will not take us down that rabbit hole.

Instead, I want to focus here on the human scale of consequences resulting from the use of categories as an aspect of language as human technology. Language is a multi-faceted tool, with other significant aspects that will have to wait for a future post. Instead, let me raise a question. If categories do not exist, then how does it matter which ones we create and how we use them? How can this matter to the forecasting and communication of weather information?

It matters in this way: the basis for categories generally serves specific purposes. For example, a number of political purposes are served by categorizing Americans by income levels, by grouping the young on the basis IQ or standardized test scores, and by creating food categories. Categories that group observations about the natural world serve heuristic purposes. Of course, other purposes can besimultaneously served. But it is important to note that heuristic purposes do not necessarily align themselves with human scale understanding and application, and that the use of one set of categories serving the development of scientific understanding does not mean these categories will therefore serve other social purposes.

Current categories about atmospheric and hydrological phenomena are not necessarily the ones that may prove to be more easily translated into practical application for people managing their day-to-day lives around work, school, sports, and social activities. In short, meteorological categories may have no natural corollary in the human social world.

And yet categories used by atmospheric scientists are thoroughly embedded in the expert knowledge and experiential wisdom embodied in weather professionals. Embedded and accepted technologies (technologies fully adopted) seem essential, crucial, and necessary. And as is so often the case with accepted technologies, these are invisible to those who wield them most commonly and with ease and grace. (Yes, I mean you, my meteorological friends!) How, then, can these be examined, critiqued, modified or even replaced?

So, what categories shall we use in communicating about weather? If the categories were changed, what ought to become the new basis? Can we maintain the scientific heuristic value if we change the basis of categories? Can we find a basis enabling us to more transparently and intuitively connect information about weather and climate to the everyday lives and experiences of people? Should we create a second level of category and language that resonates with the everyday world of human activity and serves those needs above the purposes of heuristic scientific need?


I have more questions than answers. But questions are often a good place to begin.


After all, if categories are human creations and a primary form of human communication technology, perhaps it is time the weather enterprise reconsider the bases for its primary use of language as a tool for making weather knowledge easily understood and usable by people for the full range of human planning and practice. For example, is the current scale used to categorize hurricanes a good basis for helping people to understand clearly the nature of the risks they may be facing from one? Should the thresholds for issuing messages about various forms severe weather be fixed regardless of geographic location, season, the range and scale of human outdoor activities occurring? Does expressing amount of expected potential rainfall in inches translate into local scale consequences for most people? How can we become a weather ready nationif our people cannot more easily become weather wise?

Categories Do Not Exist

by Susan A. Jasko

Recently, the following question appeared in my Twitter feed (but not directed at me): What is the origin of the threshold for calling hail “dangerous”? Similarly, much social (and other) media attention was directed at an article that raises this question: Can the choice of name for representing a tropical storm/hurricane really influence how people perceive and assess the potential for danger brought by that storm? About one year ago, many folks in the weather enterprise were asking about why, when, and whether a winter storm should be named.  It was quite a “dust-up”!

Earlier this week, wind, rain, and large hail co-occurred causing damage to cars and buildings. On social media sites, I read exchanges among weather folk (professionals and aficionados) about what to call this co-occurrence. Thunderstorm? Derecho? Land hurricane? Into which category of weather phenomenon does the observed event fall?

But categories simply do not exist – at least not outside of human language and cognition. Categories are concepts. Human-made devices engineered to help us individually and collectively make sense of the world around us. They are tools enabling humans to parse the natural and social world in ways that create the bases for leveraging resources, organizing knowledge, and establishing relationships.

Although categories do not exist independently, categorical thinking helps us to grasp how things are alike and how they differ, how things are related or not related, how things may therefore be grouped, and how things may be judged and valued. Such is the power of human language: It not only describes the world, but also recreates the world in terms of human interest and attention. Categories do matter.

Language may well be the first form of human technology, and many scholars regard it as the first form of communication media. Although we commonly think of various objects as forms of technology, including cars, cell phones, computers, and automobiles, technology also takes the form of ideas or concepts, and in very much the same way as do the physical forms, non-physical technology transforms social, economic, political, institutional, and interpersonal relations among humans.  It creates powerful, pervasive, and transformative changes.

If you are still with me, you probably noticed that I seem to be implying something like “language creates reality” Not exactly. I do not mean it in the sense that the natural (physical world) is shaped by human thinking – at least not entirely. In some sense, the current “debate” about global warming partly hinges on a disagreement about whether or not human activity can in fact alter global processes. That is, the point centers on a question about to what extent human technology and engineering can change or recreate the world. But this is not where my concern resides for present purposes, and I will not take us down that rabbit hole.

Instead, I want to focus here on the human scale of consequences resulting from the use of categories as an aspect of language as human technology. Language is a multi-faceted tool, with other significant aspects that will have to wait for a future post. Instead, let me raise a question. If categories do not exist, then how does it matter which ones we create and how we use them? How can this matter to the forecasting and communication of weather information?

It matters in this way: the basis for categories generally serves specific purposes. For example, a number of political purposes are served by categorizing Americans by income levels, by grouping the young on the basis IQ or standardized test scores, and by creating food categories. Categories that group observations about the natural world serve heuristic purposes. Of course, other purposes can besimultaneously served. But it is important to note that heuristic purposes do not necessarily align themselves with human scale understanding and application, and that the use of one set of categories serving the development of scientific understanding does not mean these categories will therefore serve other social purposes.

Current categories about atmospheric and hydrological phenomena are not necessarily the ones that may prove to be more easily translated into practical application for people managing their day-to-day lives around work, school, sports, and social activities. In short, meteorological categories may have no natural corollary in the human social world.

And yet categories used by atmospheric scientists are thoroughly embedded in the expert knowledge and experiential wisdom embodied in weather professionals. Embedded and accepted technologies (technologies fully adopted) seem essential, crucial, and necessary. And as is so often the case with accepted technologies, these are invisible to those who wield them most commonly and with ease and grace. (Yes, I mean you, my meteorological friends!) How, then, can these be examined, critiqued, modified or even replaced?

So, what categories shall we use in communicating about weather? If the categories were changed, what ought to become the new basis? Can we maintain the scientific heuristic value if we change the basis of categories? Can we find a basis enabling us to more transparently and intuitively connect information about weather and climate to the everyday lives and experiences of people? Should we create a second level of category and language that resonates with the everyday world of human activity and serves those needs above the purposes of heuristic scientific need?


I have more questions than answers. But questions are often a good place to begin.


After all, if categories are human creations and a primary form of human communication technology, perhaps it is time the weather enterprise reconsider the bases for its primary use of language as a tool for making weather knowledge easily understood and usable by people for the full range of human planning and practice. For example, is the current scale used to categorize hurricanes a good basis for helping people to understand clearly the nature of the risks they may be facing from one? Should the thresholds for issuing messages about various forms severe weather be fixed regardless of geographic location, season, the range and scale of human outdoor activities occurring? Does expressing amount of expected potential rainfall in inches translate into local scale consequences for most people? How can we become a weather ready nationif our people cannot more easily become weather wise?

Categories Do Not Exist

by Susan A. Jasko

Recently, the following question appeared in my Twitter feed (but not directed at me): What is the origin of the threshold for calling hail “dangerous”? Similarly, much social (and other) media attention was directed at an article that raises this question: Can the choice of name for representing a tropical storm/hurricane really influence how people perceive and assess the potential for danger brought by that storm? About one year ago, many folks in the weather enterprise were asking about why, when, and whether a winter storm should be named.  It was quite a “dust-up”!

Earlier this week, wind, rain, and large hail co-occurred causing damage to cars and buildings. On social media sites, I read exchanges among weather folk (professionals and aficionados) about what to call this co-occurrence. Thunderstorm? Derecho? Land hurricane? Into which category of weather phenomenon does the observed event fall?

But categories simply do not exist – at least not outside of human language and cognition. Categories are concepts. Human-made devices engineered to help us individually and collectively make sense of the world around us. They are tools enabling humans to parse the natural and social world in ways that create the bases for leveraging resources, organizing knowledge, and establishing relationships.

Although categories do not exist independently, categorical thinking helps us to grasp how things are alike and how they differ, how things are related or not related, how things may therefore be grouped, and how things may be judged and valued. Such is the power of human language: It not only describes the world, but also recreates the world in terms of human interest and attention. Categories do matter.

Language may well be the first form of human technology, and many scholars regard it as the first form of communication media. Although we commonly think of various objects as forms of technology, including cars, cell phones, computers, and automobiles, technology also takes the form of ideas or concepts, and in very much the same way as do the physical forms, non-physical technology transforms social, economic, political, institutional, and interpersonal relations among humans.  It creates powerful, pervasive, and transformative changes.

If you are still with me, you probably noticed that I seem to be implying something like “language creates reality” Not exactly. I do not mean it in the sense that the natural (physical world) is shaped by human thinking – at least not entirely. In some sense, the current “debate” about global warming partly hinges on a disagreement about whether or not human activity can in fact alter global processes. That is, the point centers on a question about to what extent human technology and engineering can change or recreate the world. But this is not where my concern resides for present purposes, and I will not take us down that rabbit hole.

Instead, I want to focus here on the human scale of consequences resulting from the use of categories as an aspect of language as human technology. Language is a multi-faceted tool, with other significant aspects that will have to wait for a future post. Instead, let me raise a question. If categories do not exist, then how does it matter which ones we create and how we use them? How can this matter to the forecasting and communication of weather information?

It matters in this way: the basis for categories generally serves specific purposes. For example, a number of political purposes are served by categorizing Americans by income levels, by grouping the young on the basis IQ or standardized test scores, and by creating food categories. Categories that group observations about the natural world serve heuristic purposes. Of course, other purposes can besimultaneously served. But it is important to note that heuristic purposes do not necessarily align themselves with human scale understanding and application, and that the use of one set of categories serving the development of scientific understanding does not mean these categories will therefore serve other social purposes.

Current categories about atmospheric and hydrological phenomena are not necessarily the ones that may prove to be more easily translated into practical application for people managing their day-to-day lives around work, school, sports, and social activities. In short, meteorological categories may have no natural corollary in the human social world.

And yet categories used by atmospheric scientists are thoroughly embedded in the expert knowledge and experiential wisdom embodied in weather professionals. Embedded and accepted technologies (technologies fully adopted) seem essential, crucial, and necessary. And as is so often the case with accepted technologies, these are invisible to those who wield them most commonly and with ease and grace. (Yes, I mean you, my meteorological friends!) How, then, can these be examined, critiqued, modified or even replaced?

So, what categories shall we use in communicating about weather? If the categories were changed, what ought to become the new basis? Can we maintain the scientific heuristic value if we change the basis of categories? Can we find a basis enabling us to more transparently and intuitively connect information about weather and climate to the everyday lives and experiences of people? Should we create a second level of category and language that resonates with the everyday world of human activity and serves those needs above the purposes of heuristic scientific need?


I have more questions than answers. But questions are often a good place to begin.


After all, if categories are human creations and a primary form of human communication technology, perhaps it is time the weather enterprise reconsider the bases for its primary use of language as a tool for making weather knowledge easily understood and usable by people for the full range of human planning and practice. For example, is the current scale used to categorize hurricanes a good basis for helping people to understand clearly the nature of the risks they may be facing from one? Should the thresholds for issuing messages about various forms severe weather be fixed regardless of geographic location, season, the range and scale of human outdoor activities occurring? Does expressing amount of expected potential rainfall in inches translate into local scale consequences for most people? How can we become a weather ready nationif our people cannot more easily become weather wise?

Categories Do Not Exist

by Susan A. Jasko

Recently, the following question appeared in my Twitter feed (but not directed at me): What is the origin of the threshold for calling hail “dangerous”? Similarly, much social (and other) media attention was directed at an article that raises this question: Can the choice of name for representing a tropical storm/hurricane really influence how people perceive and assess the potential for danger brought by that storm? About one year ago, many folks in the weather enterprise were asking about why, when, and whether a winter storm should be named.  It was quite a “dust-up”!

Earlier this week, wind, rain, and large hail co-occurred causing damage to cars and buildings. On social media sites, I read exchanges among weather folk (professionals and aficionados) about what to call this co-occurrence. Thunderstorm? Derecho? Land hurricane? Into which category of weather phenomenon does the observed event fall?

But categories simply do not exist – at least not outside of human language and cognition. Categories are concepts. Human-made devices engineered to help us individually and collectively make sense of the world around us. They are tools enabling humans to parse the natural and social world in ways that create the bases for leveraging resources, organizing knowledge, and establishing relationships.

Although categories do not exist independently, categorical thinking helps us to grasp how things are alike and how they differ, how things are related or not related, how things may therefore be grouped, and how things may be judged and valued. Such is the power of human language: It not only describes the world, but also recreates the world in terms of human interest and attention. Categories do matter.

Language may well be the first form of human technology, and many scholars regard it as the first form of communication media. Although we commonly think of various objects as forms of technology, including cars, cell phones, computers, and automobiles, technology also takes the form of ideas or concepts, and in very much the same way as do the physical forms, non-physical technology transforms social, economic, political, institutional, and interpersonal relations among humans.  It creates powerful, pervasive, and transformative changes.

If you are still with me, you probably noticed that I seem to be implying something like “language creates reality” Not exactly. I do not mean it in the sense that the natural (physical world) is shaped by human thinking – at least not entirely. In some sense, the current “debate” about global warming partly hinges on a disagreement about whether or not human activity can in fact alter global processes. That is, the point centers on a question about to what extent human technology and engineering can change or recreate the world. But this is not where my concern resides for present purposes, and I will not take us down that rabbit hole.

Instead, I want to focus here on the human scale of consequences resulting from the use of categories as an aspect of language as human technology. Language is a multi-faceted tool, with other significant aspects that will have to wait for a future post. Instead, let me raise a question. If categories do not exist, then how does it matter which ones we create and how we use them? How can this matter to the forecasting and communication of weather information?

It matters in this way: the basis for categories generally serves specific purposes. For example, a number of political purposes are served by categorizing Americans by income levels, by grouping the young on the basis IQ or standardized test scores, and by creating food categories. Categories that group observations about the natural world serve heuristic purposes. Of course, other purposes can besimultaneously served. But it is important to note that heuristic purposes do not necessarily align themselves with human scale understanding and application, and that the use of one set of categories serving the development of scientific understanding does not mean these categories will therefore serve other social purposes.

Current categories about atmospheric and hydrological phenomena are not necessarily the ones that may prove to be more easily translated into practical application for people managing their day-to-day lives around work, school, sports, and social activities. In short, meteorological categories may have no natural corollary in the human social world.

And yet categories used by atmospheric scientists are thoroughly embedded in the expert knowledge and experiential wisdom embodied in weather professionals. Embedded and accepted technologies (technologies fully adopted) seem essential, crucial, and necessary. And as is so often the case with accepted technologies, these are invisible to those who wield them most commonly and with ease and grace. (Yes, I mean you, my meteorological friends!) How, then, can these be examined, critiqued, modified or even replaced?

So, what categories shall we use in communicating about weather? If the categories were changed, what ought to become the new basis? Can we maintain the scientific heuristic value if we change the basis of categories? Can we find a basis enabling us to more transparently and intuitively connect information about weather and climate to the everyday lives and experiences of people? Should we create a second level of category and language that resonates with the everyday world of human activity and serves those needs above the purposes of heuristic scientific need?


I have more questions than answers. But questions are often a good place to begin.


After all, if categories are human creations and a primary form of human communication technology, perhaps it is time the weather enterprise reconsider the bases for its primary use of language as a tool for making weather knowledge easily understood and usable by people for the full range of human planning and practice. For example, is the current scale used to categorize hurricanes a good basis for helping people to understand clearly the nature of the risks they may be facing from one? Should the thresholds for issuing messages about various forms severe weather be fixed regardless of geographic location, season, the range and scale of human outdoor activities occurring? Does expressing amount of expected potential rainfall in inches translate into local scale consequences for most people? How can we become a weather ready nationif our people cannot more easily become weather wise?

Categories Do Not Exist

by Susan A. Jasko

Recently, the following question appeared in my Twitter feed (but not directed at me): What is the origin of the threshold for calling hail “dangerous”? Similarly, much social (and other) media attention was directed at an article that raises this question: Can the choice of name for representing a tropical storm/hurricane really influence how people perceive and assess the potential for danger brought by that storm? About one year ago, many folks in the weather enterprise were asking about why, when, and whether a winter storm should be named.  It was quite a “dust-up”!

Earlier this week, wind, rain, and large hail co-occurred causing damage to cars and buildings. On social media sites, I read exchanges among weather folk (professionals and aficionados) about what to call this co-occurrence. Thunderstorm? Derecho? Land hurricane? Into which category of weather phenomenon does the observed event fall?

But categories simply do not exist – at least not outside of human language and cognition. Categories are concepts. Human-made devices engineered to help us individually and collectively make sense of the world around us. They are tools enabling humans to parse the natural and social world in ways that create the bases for leveraging resources, organizing knowledge, and establishing relationships.

Although categories do not exist independently, categorical thinking helps us to grasp how things are alike and how they differ, how things are related or not related, how things may therefore be grouped, and how things may be judged and valued. Such is the power of human language: It not only describes the world, but also recreates the world in terms of human interest and attention. Categories do matter.

Language may well be the first form of human technology, and many scholars regard it as the first form of communication media. Although we commonly think of various objects as forms of technology, including cars, cell phones, computers, and automobiles, technology also takes the form of ideas or concepts, and in very much the same way as do the physical forms, non-physical technology transforms social, economic, political, institutional, and interpersonal relations among humans.  It creates powerful, pervasive, and transformative changes.

If you are still with me, you probably noticed that I seem to be implying something like “language creates reality” Not exactly. I do not mean it in the sense that the natural (physical world) is shaped by human thinking – at least not entirely. In some sense, the current “debate” about global warming partly hinges on a disagreement about whether or not human activity can in fact alter global processes. That is, the point centers on a question about to what extent human technology and engineering can change or recreate the world. But this is not where my concern resides for present purposes, and I will not take us down that rabbit hole.

Instead, I want to focus here on the human scale of consequences resulting from the use of categories as an aspect of language as human technology. Language is a multi-faceted tool, with other significant aspects that will have to wait for a future post. Instead, let me raise a question. If categories do not exist, then how does it matter which ones we create and how we use them? How can this matter to the forecasting and communication of weather information?

It matters in this way: the basis for categories generally serves specific purposes. For example, a number of political purposes are served by categorizing Americans by income levels, by grouping the young on the basis IQ or standardized test scores, and by creating food categories. Categories that group observations about the natural world serve heuristic purposes. Of course, other purposes can besimultaneously served. But it is important to note that heuristic purposes do not necessarily align themselves with human scale understanding and application, and that the use of one set of categories serving the development of scientific understanding does not mean these categories will therefore serve other social purposes.

Current categories about atmospheric and hydrological phenomena are not necessarily the ones that may prove to be more easily translated into practical application for people managing their day-to-day lives around work, school, sports, and social activities. In short, meteorological categories may have no natural corollary in the human social world.

And yet categories used by atmospheric scientists are thoroughly embedded in the expert knowledge and experiential wisdom embodied in weather professionals. Embedded and accepted technologies (technologies fully adopted) seem essential, crucial, and necessary. And as is so often the case with accepted technologies, these are invisible to those who wield them most commonly and with ease and grace. (Yes, I mean you, my meteorological friends!) How, then, can these be examined, critiqued, modified or even replaced?

So, what categories shall we use in communicating about weather? If the categories were changed, what ought to become the new basis? Can we maintain the scientific heuristic value if we change the basis of categories? Can we find a basis enabling us to more transparently and intuitively connect information about weather and climate to the everyday lives and experiences of people? Should we create a second level of category and language that resonates with the everyday world of human activity and serves those needs above the purposes of heuristic scientific need?


I have more questions than answers. But questions are often a good place to begin.


After all, if categories are human creations and a primary form of human communication technology, perhaps it is time the weather enterprise reconsider the bases for its primary use of language as a tool for making weather knowledge easily understood and usable by people for the full range of human planning and practice. For example, is the current scale used to categorize hurricanes a good basis for helping people to understand clearly the nature of the risks they may be facing from one? Should the thresholds for issuing messages about various forms severe weather be fixed regardless of geographic location, season, the range and scale of human outdoor activities occurring? Does expressing amount of expected potential rainfall in inches translate into local scale consequences for most people? How can we become a weather ready nationif our people cannot more easily become weather wise?