Weather Spotters: The Eyes and Ears of the NWS
During a severe weather event, be it a tornado or a hurricane, a flash flood or a severe thunderstorm, many find themselves glued either visually or auditorily to a news station. There they eagerly await the latest weather update from their local meteorologist to be informed as to whether they and their possessions will be affected by the impending weather. In times like these, up to date and real-time information regarding a severe weather event is critical in helping to provide “warnings for the protection of life and property,” per the mission statement of the National Weather Service. Though, how is this real-time information relayed to the NWS who then disseminate it amongst TV and radio broadcast stations to inform the public?
One of the greatest resources the NWS has for garnering reports during a severe weather event is volunteers. These volunteers for the NWS are called “Weather Spotters,” and hold the important task of informing their local NWS branch of hazardous and severe weather conditions in their area. With these volunteer reports, the NWS may then warn and inform the surrounding public of dangerous conditions within the area, so that appropriate action may be taken to protect life and property.
As a weather spotter, these volunteers have the responsibility of reporting during severe weather conditions what they have seen, when and where they have seen it, and to identify themselves and their location. By providing this information, the NWS can then use this to help identify the severity of the threat to surrounding communities alongside radar and satellite reports. Many times, these weather spotters can be sources of real-time confirmation for certain weather phenomena indicated on radar. For example, in the event of radar-indicated rotation, weather spotters may be able to visually confirm this to the NWS if the storm rotation happens to be within their vicinity. Some examples of what kinds of weather phenomena spotters may report to their local NWS branch includes things of high priority such as tornadoes, flash flooding, and funnel clouds, to lower priority events such as winds in excess of 40mph or hail of ½ an inch in diameter or greater. Depending on ones geographic location, what is classified as high versus low priority may change depending on their locally-defined criteria.
As some of the front lines in reporting severe weather conditions, Weather Spotters alongside the excellent work of NWS meteorologists do help save lives. They are often the first to see and experience alarming or dangerous conditions out in the field that meteorologists in the office may only be seeing as radar and satellite reports. These volunteer reports help to convey the gravity of a situation and enable meteorologists and broadcasters to diffuse important data and information much more effectively to the public. Many NWS branches offer free online courses to the general public in order to become trained as a weather spotter, no experience needed. Simply a desire to help the community and an ability to communicate hazardous conditions is needed to become trained as a Weather Spotter!
To learn more about weather safety and preparedness be sure to click the link: https://www.globalweatherclimatecenter.com/weather-safety-educational-topics
© 2018 Weather Forecaster Alexis Clouser
Image credit: weather.gov
Whether it’s rain, snow, freezing rain, sleet, or even freezing drizzle, knowing what precipitation is occurring is extremely important to understand. This is especially vital during the winter where temperatures can often hover right around the freezing mark, and precipitation can change from snow to rain very easily. During the winter months in the Northeastern region of the United States, temperatures tend to fluctuate quite often between freezing and above freezing. This location specifically is a hot spot for mid-latitude cyclones to come across the country where the combination of both warm and cold frontal boundaries can pass over an area within a matter of hours. This creates many opportunities for a wide range of precipitation to fall and it’s important to a forecasting meteorologist to be as accurate as possible when looking at what to expect from an atmosphere that can be quick to change its course.
A great way to look at possible precipitation is by analyzing the layers of the atmosphere starting from the top and working down to the surface. This can be done by looking at a sounding that looks at a vertical profile of the atmosphere showing how the temperature is changing with height. Below is an example of common types of precipitation formed dependent upon certain conditions.
A typical rule to follow is that if you have air warmer than -10 degrees Celsius, there won’t be any ice initiation, or ice forming around a rain drop within the layer. If air is colder than -10 degrees Celsius, then there definitely can be ice initiation. The follow up questions would be, is there icing occurring in the upper layers? Is there a warm layer where snow could fall into and melt? A hydrometeor, or any product of atmospheric water vapor that falls as precipitation, typically stays as snow if the layer is below 1 degree Celsius and can melt into liquid water in a layer that’s above 3 degrees Celsius. Considering the wet bulb effect of a warm layer can also be helpful because it can tell you how much water vapor is present in the air based on the evaporation of water, and how that can decide the type of precipitation as well. For example, if the wet bulb temperature is below -10 degrees Celsius in a cold layer, and the surface is above around 1.5 degrees Celsius, then you could get sleet as precipitation.
In the event of a Nor’easter, precipitation can vary greatly depending on the time of year it occurs. Even the sea salt in the oceans can have an effect on the type of precipitation and act to enhance ice nuclei to activate the snowflake process.
Something to note is that these tips are NOT an entirety of depicting the characteristics of the atmosphere, as precipitation type forecasting is not an exact science. The analysis of multiple variables and layers of the atmosphere is required, proving to be a significant challenge in forecasting. The different techniques to approach this add to the complexity of this method as well.
It’s also important to know what is currently happening outside regardless of the forecasting situation. Using the current conditions to predict minute-by-minute events is utilized in situations where the atmosphere is changing rapidly than models and forecasters can grasp.
It is too often it seems that the difficulty of forecasting the precipitation type has been a cause of major accidents and hazardous situations that catch the public off guard. Having such variable temperatures in mid-latitude cyclones can lead to the melting and freezing of water on roadways that can cause ice jams in rivers as well as flash freezing on highways. Freezing drizzle, for example, may seem like a minor event, but even a trace of it with below freezing temperatures at the surface can become a very dangerous event.
Often, meteorologists can be too focused on the “big events” and neglect to recognize how much of an impact the change in temperature by a couple of degrees can affect people that need to walk and drive to get to where they need to go. People walk down their driveway, slip and get very injured due to black ice, and cars and buses go off the roads, which is why it’s so vital to be aware of these events. It can be a very tough decision for forecasters as well as administrators when trying to keep children safe on their way to school. Meteorologists and forecasters understand the weight of their decisions and believe in focusing on the small details that can make or break a forecast. Therefore, understanding the precipitation type is a valuable skill to have during any weather event, and helps us understand the atmosphere even more as it unfolds in front of us.
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© 2019 Weather Forecaster Christine Gregory
DISCUSSION: During any given Winter-time season, there are millions of people who are seasonally impacted by substantially to severely cold weather and/or major snowstorms which can slow down or even halt ground and air travel networks across various parts of North America, Europe and beyond. Moreover, one of the more “annoying” parts of classic winter storms for many people living in these areas is the infamous process of “post-storm cleanup.” Despite the natural power and beauty contained within the most classic snowstorms in recorded history, there are still major threats which exist well after the snowstorm has released its final snowflakes to the surface of the Earth. Some commonplace examples include (but are certainly not limited to) weighted and/or downed trees and power lines, black ice create dangerous (or even life-threatening) road and airport conditions for prolonged periods well after the conclusion of any snowstorm, bone-chilling conditions which can bring about frostbite and/or hypothermia if anyone is not sufficiently well protected from the outside weather elements.
However, one such natural hazard which most people do not usually think of (or take into legitimate consideration) right away is the natural danger involved with having large amounts of snowfall left on the tops of automobiles of any size. The primary reason for why this is such a dangerous issue to contend with is the fact that when snowfall is left atop automobiles, it will often compact as the pressure of the accumulated snowfall presses down upon itself and effectively forms a solid “snow slab.” This is especially dangerous (and even life-threatening under the right circumstances) since (as shown in the Tweet embedded above courtesy of the AMHQ at The Weather Channel in Atlanta, Georgia), solid snow slabs atop automobiles of any size can easily become airborne projectiles when an automobile accelerates to greater speeds on local or state-wide highways. When this happens, it can quickly threaten the safety and well-being of all passengers traveling in vehicles of any kind which are following the vehicle with the snow left atop of it.
Therefore, as explained in the brief video clip (by Meteorologist Jen Carfagno of The Weather Channel) attached above, there is no debate that it is ALWAYS imperative to clean all the accumulated snow and ice of your car. This way, you can be more certain that your driving will not endanger the lives of others around or behind you on the open road.
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© 2019 Meteorologist Jordan Rabinowitz