Ask Terri Archive

Weather and Climate

Air and Air Pressure

• Please explain a high pressure or low pressure area, I can't grasp the concept. Whenever I hear the word pressure, I think of compressed air in a bottle or tire being either high or low pressure.

• What is the pressure differential between Isobars and what is the reference point? What is the relationship between wind speed and the proximity of adjacent isobars?

• Is high pressure warmer than low pressure or is high pressure colder than low pressure.

Air Pollution and Ozone

• Is acid rain still a problem?

Atmosphere

• Can you tell me about the different layers of the atmosphere?

• What has happened to the Arctic highs that we once saw on a regular basis; and is the jet stream's movement as more of a straight line over the earth here to stay? Is this change related totally on the warming Pacific Ocean?

Careers and Education

• How do you become a meteorologist?

• Hi Terri, I have a grandson that is almost 10 that has shown an interest in meteorology. I wander if you have any suggestions for games or items that will help grow this interest. Thanks for your help with this. Anita O’Kelly

• My 9 year old is doing a science project on global warming. Is there a resource for Charlotte information?

Clouds and Fog

• I've seen contrails that have lasted for hours. Other times they seem to disappear as soon as they form. Why is this?

• Why are cumulus clouds flat on the bottom?

• I recently read an article about a gravity wave that traveled from Alabama to Bridgewater, NC (which is about 2 miles from my house). Can you offer additional information on this weather pattern or system? How often do these happen?

• How do clouds form?

• How can clouds make rain fall on most parts of the world at one time?

• What is fog made of?

• Why are some clouds white?

• My wife asked me what frozen fog is called. Does fog freeze? If it does what is it called?

Drought

• Since the drought is such a huge concern for our area, I would love to see a daily drought update. Does your site have one? How are we doing with the drought?

• How much rain do we need until we're out of this drought?

• During this period of drought, I've noticed that the few thunderstorms we have had over the summer (mainly August and September) have had a high amount of lightning. Is there any correlation between the dry weather and the accumulation of stat

• With the drought that ended in 2002, from which we never really recovered, and now this latest drought, how much rainfall do we actually need to replenish the groundwater to its normal level?

• How long do you expect our drought to last? When will we know that it is over?

• Without any rain in the forecast and the water restrictions we are currently under do you suggest having our lawn aerated and overseeded? We live in South Charlotte. Thank you.

El Nino and Global Circulations

• I know we are in a La Nina phase, hence the drought. Is it going to end soon and get us back in El Nino which gets us more rain? Also do you really believe in global warming or do you think like I do that weather patterns are cyclical? Thanks

Forecasting

• What is meant by "unstable air" and "upper level disturbance" in weather reporting?

Fronts

• What is a front and what do they do?

Global Warming and Climate Change

• Do you think global warming is responsible for the warmer temps and the reduced number of white Christmas's throughout the country?

Heating and Cooling Degree Days

• Can you teel me how to find the number of heating tempature days yr to date in zip code 04915? We are moving there.

Humidity and Dew Point

• Conditions determine the effectiveness of scenting dogs & helps or henders their performance. is the scenting conditions better with a high dew point and high Humidity or low for each. Your answer will be very helpful.

• Is there a simple way (maybe by using a math formula) that we can take the humidity reading and the air temperature to arrive at a "ballpark" dewpoint temperature??

• What is an ideal humidity range for inside the home? Does this measurement change with different weather outside?

• Why isn't the humidity index at 100% when it's raining?

• I have noted that in the summer, the relative humidity usually decreases as the day proceeds. Can any summertime generalizations be formulated as to what happens to dewpoints during the course of the day? As you have said, dewpoint is a more important ind

• How is the dewpoint calculated?

• Is there a difference between the terminology "humidity" and "relative humidity"?

• What exactly is the dewpoint and how do you forecast it?

• Lately, I've noticed that I'm getting shocked by static electricity more often and with greater intensity than previous months. It usually happens when I'm getting out of my car. Does this have anything to do with the weather?

Hurricanes and Tropical Storms

• Which hurricane lasted the longest amount of time?

• What is the relationship between barometric pressure and wind speeds inside a cyclone?

• Can two hurricanes merge together?

• Why do hurricanes need warm water to survive?

• What is the fujiwhara effect?

• Why do the meteorologists switch from inches of mercury to millibars ONLY when a hurricane is being tracked?

• How are hurricanes named?

• What’s the difference between a tornado and a hurricane?

• Given the latest report from the NHC, do you think that the vertical wind shear across the Atlantic Basin will reduce the number of Hurricanes in the 2008 Season. I know ocean water temperatures still seem a little high for this time of year.

• What is the difference between a hurricane, typhoon and cyclone?

Instruments and Weather Prediction

• Is the most accurate design for a rain gauge one in which the diameter is constant - that is, a simple graduated cylinder? Sometimes you see one where the top is somewhat wider than the rest of the cylinder.

• How accurate is the rain gauges you purchase at your local hardware store compared to the gauges a meteorologist would use?

• What is hygrometer? What are the other instruments that are used for getting the weather information?

• Have meteorologists become too dependent on computer models and stopped using their own learned skills and instincts?

• Why is it so hard to forecast whether it will rain, sleet or snow?

• Which equipment do you recommend for a "backyard wx station"? I'd like to consider equipment that can be read remotely by my Windows XP computers.

• How do the farmers almanac predict out so far and what is the accuracy? They predicted Drought in southeast for 2007 in the one I got mid 2006.

Nature and Weather

• My neighbour says that when the leaves on the trees in our neighbourhood turn to show their underside that there is going to be a storm. Is she right?

• Does the weather have anything to do with all the Black Birds we have been seeing in the Huntersville area. For the past three weeks, we have been seeing on a regular basis over a thousand black birds in our yard and trees. They make an awful noise and

• Why did the leaves on the trees in our yard turn colors and fall off so early this year?

Personal Weather Station Network(PWS)

• What is required to be set up as a weather station for the Weather Underground? There seem to be none here in Fort Mill, SC.

• Would it not be a good idea to have a weather station insinde the loop road? In say, 28211. We live on Colony Road, near Runnymede and would be willing to have one in our garden. How is it done?

• When will you have a weather station in Pineville?

• The weather stations you list in eastern Huntersville appear very close to one another and yet they regularly show a difference of 8-12 degrees in temperature?

• How does one become a weather tracker? Are the weather stations in peoples yards? I'd be willing to have one in mine if you're looking for others.

Rain, Snow and Ice

• What is a 'rain shadow'?

• How can we smell rain?

• Can rain flood my neighborhood?

• I know that this sounds like a long shot, but with all of the historical information about La Nina and El Nino and other weather patterns, and how they have impacted the various ski areas, it seems that you should be able to predict if Colorado will have

• Years ago, cloud seeding with silver iodide was used, to try to coax more rain out of the clouds. Is this something that is no longer useful? Could it help the drought situation?

• Is rainwater or snow safe to drink with all of the pollutants that may be in it?

• How big can a raindrop be?

• What is the difference between isolated and scattered showers?

• How can I find the "average" monthly and yearly rainfall for my immediate location so that I can track rainfall as measured in my back yard again the "average"??

• When you say that there is a 50% chance of rain, does that mean there is a 50% chance it is not going to rain or that 50% of the viewing area is going to get rain?

• What’s the difference between hail and sleet?

• I remember when I was growing up, we used to make snow cream. My wife Bernie recently asked me if that was really safe(to eat snow), and I said we better ask you-Terry, the expert...is it safe? was it 30 years ago? is it now? I was always told to never ea

• Why does it warm up everytime we get snow?

• I heard that there is a 10:1 rato of snow:water. Is that true for the snow we have in North Carolina "wet snow" versus the snow in Utah "dry snow", due to the humidity levels? If it's different, what are the ratios? Thanks.

• What type of gauge is used to measure snow?

• Ice and snow are predicted for Thursday morning. Usually that just happens in the north part of the county. How can I check on south meck weather without getting all caught up in the drama of the snow?

• What is the record amount of snow in the past 25 years?

• Why does it seem like it never snows in Charlotte. It seems that when we have cold air in place we never have the moisture, and when we have the moisture we never have the cold air.

• My daughter (Julie)and I have a disagreement on when we last had snow in Charlotte on Christmas. I say not since we have lived here. (1973) She disagrees and says we have. When was it? (A lunch is riding on this.)Thanks!

• Do you think we'll ever have snow like we used to back in the 80's? In the 80's we used to have several feet of snow in Charlotte. It hasn't been like that in a while and I'm wondering if we'll ever have that again.

• What is the ratio of snow to water in terms of number of inches. In other words, if we get 10 inches of snow, how many inches of rains would this help us make up. Thanks.

Seasons and Climate

• When are the 'dog days' of summer?

• When is the driest time of the year in Charlotte?

• Terri, we have been hearing for several years now that rainfall is "below average". It seems to me that we need to re-calculate a new "average". What do you think?

• We have had some miserably hot weather recently. However, the Dog Days will be with us soon. When will these officially arrive?

• What type of climate does Charlotte North Carolina have?

• How do the Appalachian Mountains affect our weather?

• What is the best place to check monthly precip totals by day and by hour - can you please give web location(address)?? THANKS!!

• What is Indian Summer?

• Will it snow this year? One of my friends said the we a white winter. But, i don't really understand why.

• Do you think we are going to have a wet winter in our area and more importantly the mountains. Will the Catawba will get adequate runoff to help the drought?

• What’s the weather like in Afghanistan and Iraq at this time of the year?

Severe Storms

• Who issues the severe storm warnings that crawl on the bottom of the tv?

• Many times you see severe thunderstorm systems weaken from what they were in the midwest when they reach us. i was wondering if the Appalachian Mts. have anything to do with that and do they possibly disrupt the storm systems?

• Which city gets more severe weather Charlotte or Atlanta?

• How dangerous are floods?

• I enjoyed your visit to Charlotte Country Day yesterday. I'm in 1st grade, and my question is do tornadoes really twist?

Severe Weather Safety Tips

• Where is the safest place during a lightning storm?

Temperature

• What is the formula for converting Fahrenheit (F) to Celsius (C)?

• Don't you think the first part of June has been unusually warm here in North Carolina?

• During this recent heat wave (June 2008) did we ever actually hit the century mark in temperature?

• Why does it feel so much cooler in the shade of a large tree as opposed to the shade of a building?

• What exactly is a "cold wedge”? I hear you mention this quite often but have no idea to what you’re referring.

• What is the coldest temperature ever recorded in Charlotte?

• What is the projected date for the last frost in spring 2008?

• What are heating degree days?

• Last year on the coldest night in January, my bedroom window popped and cracked in the middle of the night. I was awake and saw it happen so I know nothing hit it to break it. Two nights ago, my garage window cracked in the middle of the night. Is it

• What is a 'cold wedge'?

Thunderstorms

• How do you measure where the lightning is striking?

• How many days a year do we have thunderstorms?

• Is there really any such thing as heat lightning?

• What is ball lightning and how is it formed?

• How do pop-up thunderstorms develop seemingly out of the blue?

• How do thunderstorms pop up seemingly out of the blue?

• What happens if an airplane is struck by lightning?

• What is the worst kind of weather in Charlotte?

• Is a tornado a cloud?

• How does lightning happen?

• Why is turbulence often associated with stormy weather?

• Why does thunder come as single loud and sharp KABOOM and other times it comes as long drawn-out rumbles.

• How much distance does each second measured between a lightning stroke and a bolt of thunder?

• Can lightning pass through a vehicle window?

• Why has there been so much severe weather this spring?

• What is ball lightning?

• Can tornadoes happen in the mountains?

• Why does lighting sometimes go in zig zags?

• Is it true that lightning comes out of the ground and not down from the sky?

• What part of the Carolinas gets more tornadoes?

• What is a derecho?

Weather Folklore

• Is “If smoke from a chimney moves towards the ground, then it will snow” scientifically true?

Wind

• If winds come from the south to the southwest for much of the year in Mecklenburg County does that mean that there is less overall air pollution in the south and southwest part of the county?

• Why do the weather people not report on the wind velocity that we have had over the past 3 months. 10-20 to 30 mph every day. What is going on here in May.

• What is a dust devil?

• Does a strong wind come every time the weather changes?

Space

Asteroids, Comets and Meteors

• What is the difference between a comet, meteor and meteorite?

• How bright is Comet 17P Holmes? I thought that I was seeing it but now I am not sure.

Moons

• Is the moon made of rock?

• Is there a “dark side” of the moon?

Planets

• Which planet was rising with the full moon last month (June 2008)?

• I have always heard that stars twinkle and planets have a steady light. Is there any truth to this?

Space Shutte and Space Station

• All the times that I have ever seen to view the International Space Station have been when the sun's light is reflecting off of it. Is it possible to see the ISS by moolight?

Stars

• What is the closest star to Earth?

• I have read that stars visible to the naked eye range in magnitude from about -1.4, the brightest, to about 6, the faintest. But what about some of the many other visible celestial objects?

• When can I see a shooting star?

• What is the closest star to earth? What is it called and how far away is it from us?

• After observing the lunar eclipse with a less than stellar telescope, I would like to get a decent telescope for my husband for our night sky viewing. Do you have any suggestions, or could you direct me somewhere that would be helpful in my search? Than

Sun

• If it takes 8 ½ minutes for light from the sun to reach the Earth then at sunset, when we see the sun dip below the horizon, did it really happen 8 1/2 minutes ago?

• What is the definition of twilight?

• How does the sun shine?

• Are aurora's more common during certain parts of the year?

• I am trying to find a website that will give me the suns elevation angle vs. time/date at our lat. long.. I used one previously but can't find one that works.

Planet Earth

Atmosphere

• How does the tilt of the Earth affect our temperature?

• What does the Air Quality Index number represent in the air quality forecast.

• What are noctilucent clouds?

• What is the difference between good ozone and bad ozone? And where is each found?

• Is the sunrise and sunset time listed for one city in a single time zone, the same as all other cities in the time zone?

• What are sundogs?

• Why are we seeing more colorful sunsets this time of the year compared to the other seasons?

Earth Rotation and Revolution

• Does the Earth leave a heat trail as it travels around the sun?

• What is the tilt of the Earth?

• How fast does the Earth turn?

• Does the Earth receive the same amount of sunlight each day?

Earthquakes

• Can you tell me how the tsunami of December 2006 changed the planet?

• Is Charlotte located in an earthquake zone?

• The news continues to talk about aftershocks that are still hitting China. At what point is it no longer an aftershock and becomes a new earthquake?

• What causes Earthquakes?

• What is the worst earthquake ever to strike the U.S.?

• I’ve heard that there is a fault line that runs through our area. Is this true? How likely is an earthquake in this area?

• Is Charlotte located in an earthquake zone?

Magnetic Field

• Is there a difference between east and TRUE east?

• On March 20th we'll be having the spring vernal equinox, and this is the time the sun is cross directly over the Earth's equator. So when the sun rises on the morning of March 20th; how many degrees north of true east will the sun rise in the Charlotte ar

Nature

• How much water does that big tree in the front yard drink?

• With the sporadic weather this spring thus far, when will be a safe time to plant roses, camellias, and hydrangeas?

• When it rains and you're in a field you'll get wet. If you're under a leafy(?) tree, you may stay dry - How does the rain that falls on a tree get to the ground? Just drips or travels down the branches to the trunk?

Oceans, Rivers and Watersheds

• What is a rip current?

• Are there tides in the Great Lakes, Mediterranean Sea and Black Sea.

• What causes tides at the beach?

• Why are there not always two high and two low tides listed per day on tidal charts?

• What happens to all the salt in the seawater when it rains?

• Is our water table here in the Charlotte area still in the negative or have we made much needed gains?

• For thousands of years billions of gallons of fresh water has been flowing from rivers into the oceans,not to mention rain water over the oceans. How does the oceans stay salty? Are they less salty today than 10,000 years ago?

• Could the Catawba ever dry up?

• Not too long ago you did an excellent video on how we pollute our water. Is it somewhere we can still access it, and if it isn't, why isn't it??

• What is the lake norman record low water level?

• What aquifers feed the private wells in our state and what effect has the drought had on them, or do we know? Are the aquifers fed by anything other than rainfall?

• What happens to all the water that goes from the septic tanks into the drain fields? Does it drain to our drinking water supply?

• Is Lake Norman going back up next spring ? I am getting tired of looking at this mess. I have seen the lake correct itself in the past, but this is far from the norm.

Miscellaneous

• Can you share with us when your 1 year non-compete is over with WCNC.

• Have you ever been in a tornado? And what it the biggest hurricane?

• What is transpiration?

• I'm always hearing that we should mow our lawns after 6:00pm. Is early morning an ok time to mow and how early should it be?

• At one time, before my previous computer died, I had a web site bookmarked from which I could get daily highs, lows, humidity and precipitation for virtually any city in the US going back monthly for many years. Now I can't find the site again.Are you awa

• Did I hear correctly that you had suggested a tablet to put in rain barrels that would discourage mosquitos? If so, what is it?

• In the days before satellites and GPS how was the elevation of a particular point determined?

• In the interest of water conservation, does moving water, ie, in a swiming pool/water garden evporate more quickly than standing water? Would it be cost wise to have timers on pool/water garden? Thanks,

• Why does Easter come so early this year?

• Does sound travel through hot air faster than cold air?

• When do we change our clocks?

• Why did you leave WCNC? We miss you.

• Will you be back on TV after the "no compete" clause expires? I miss your broadcasts terribly.

• How did you learn to predict football so well?

• When are you going to add some gardening info to you great site?