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Recent Questions

Question: I have lived in NC most of my 61 years. I don't remember hearing of so many tornado events as I was growing up or even as an adult until recent years. Has anything other than availability of information and real time coverage of these events changed? Do you think we will see more severe weather or less based on your knowledge of climatic change in the coming months? — Mary Glisson

Answer: You've hit upon what appears to be the main influence in terms of an apparent trend toward increasing tornado frequency when you view the number of tornadoes in our state per decade, which shows, for example, 71 in the 1950s and 81 in the 1960s, ranging up to 306 in the 1990s and 305 in the 2000s.

The increase in population, increase in communications technologies such as mobile phones, and most especially the implementation of a network of Doppler weather radars have all combined to make it much easier to detect weak and very short-lived tornadoes that may have gone completely unnoticed in the past. A few recent tornadoes were even documented that only had path lengths of one-quarter mile each. More intense, long-lived and highly damaging or deadly tornadoes, those of the EF-3 and EF-4 intensity levels, when looked at over the decades, went from 7 and 5 in the 1950s and 1960s, respectively, to 8 and 3 in the 1990s and 2000s. Since these kinds of tornadoes were usually documented even before the increase in radar coverage and other communications technologies, this gives a fairly strong sense that the main reason for the increasing trend is that we can now detect many brief and weak tornadoes that would have been missed in the past.

In the coming months, we will be heading into summer, when most of our severe weather is in the form of occasional pulse-type thunderstorms that tend to produce isolated instances of strong winds and pockets of large hail, but relatively little in the way of tornadic activity. Also, we are heading into a probable El Nino pattern, which often lowers the number and intensity of Atlantic hurricanes.
Jun. 5, 2014 | Tags: past weather, tornadoes

Question: How could La Nina affect weather during the summer in North Carolina? — Luz Roman

Answer: La Nina is a condition in which the central and eastern equatorial Pacific has below normal sea surface temperatures. When that is the case through the summer, there aren't many direct effects on NC weather, but the pattern does tend to lead to active hurricane seasons in the Atlantic, and can increase the number of tropical cyclones or their remnants that affect our area. There is also some tendency toward more tornadoes in La Nina years, although this mainly applies outside the summer months.

We are currently not under La Nina or El Nino (opposite of La Nina) conditions, but it appears there is a good chance (approaching 70% by late summer) an El Nino pattern will develop this summer. That could mean somewhat suppressed Atlantic tropical cyclone activity, and potentially drier than normal conditions for our state.
Jun. 4, 2014 | Tags: el nino/la nina

Question: How did Ask Greg start? — Hope Beltran

Answer: In the early days of "WRAL OnLine" (now WRAL.com), around 1996, we had meetings to brainstorm content for the weather section of the web site, and Mike Moss suggested we consider a local question and answer feature more or less modeled on the "Ask Jack" weather column that ran in USA Today at that time. Not long after, a section of our web site called "Ask the Meteorologist" was implemented and we began posting answers to viewer/visitor-submitted questions. A few years later, we began providing weather forecasts for the local newspaper, and also included a shortened version of the question and answer column there. The name of the column there was "AskGreg," to go along with the photo printed on the page. For consistency, we eventually changed the name of our online Q&A function to "AskGreg" as well, and it continues all this time later in its current form.
Jun. 3, 2014 | Tags: wral.com

Question: What were the dates that hail came down in March/April 2014 in Durham? I collected the specimens and left them in my freezer and needed to know the exact dates the hail fell? — Alice

Answer: We checked a database of local storm reports for Durham County covering March and April of this year, and found hail reports for the Durham area from the afternoon of April 25, with sizes up to one-inch in diameter. No hail reports were found for March, but there were sleet reports for Durham on March 3rd, 17th and 18th.
Jun. 2, 2014 | Tags: hail, past weather

Question: When we have bad weather, did you ever have to sleep in the news station? — Celyn M.

Answer: Some bad weather situations, such as the passage of hurricanes, snow storms or ice storms, do result in very long work days for meteorologists and other employees of the station (as they do for many occupations, like medical workers, emergency responders, power crews, law enforcement and a number of others). Instead of sleeping at the station, however, in most cases the company will reserve a block of rooms for employees in nearby hotels, and if necessary shuttle us back and forth to work in 4-wheel drive vehicles.
Jun. 1, 2014 | Tags: preparedness, wral.com

Question: Could you be picked up by a tornado, then where the tornado weakens, could you be put down without harm? — Will Atkinson

Answer: There have been very rare instances in which people were lifted or thrown by the strong winds in tornadoes, sometimes on their own and sometimes with another object, and landed softly enough to escape serious injury. However, this is very rare and in most cases those who are thrown significant distances in tornadic winds are either seriously injured or killed, in some cases by the direct force of the landing, in many others due to being struck by other objects being blown along in the high winds.
May. 31, 2014 | Tags: tornadoes, weather & health

Question: Just saw a bright orange vessel in the sky... Wouldn't be the space station or a satellite we don't think..... Do you know if there were rockets launched at 10 pm EDT Saturday at Wallops Island VA? — Amy Farabow

Answer: We checked NASA's launch calendar and found that the only launch this month was a space station crew change mission from Baikonur in Russia, with the next Wallops Island launch scheduled for early June. You can check that schedule at www.nasa.gov/missions/calendar/index.html. We can't say for sure what else you might have observed based on the description you gave, but do wonder if perhaps someone in the area may have launched a sky lantern, like the ones described at en.wikipedia.org/wiki/Sky_lantern.
May. 30, 2014 | Tags: astronomy, cool sites

Question: Why is it that the boundary layer high temperature is so dependent on the height of different levels of the atmosphere? It seems like I've read in forecast discussions and such that the "H5 temperature will be x today and there will be clouds breaking around midday that should allow enough sun to reach full heating potential." If there were sun all day, wouldn't we see a warmer high? I know that the airmass (and the atmospheric heights) play a role, but it is hard to fathom that the temperature on a bright sunny day in mid-May can be tempered so much by an arbitrary height, while on another day even modest sun can allow us to reach "full heating potential" that results in a much higher temperature. Thanks! — John L

Answer: It's less the case that those low level temperatures are dependent on the heights of certain levels than it is that they are interrelated. The height of a certain pressure level, such as "H5," which is shorthand for the 500 millibar pressure surface, is partly a function of the average temperature of all the layers below it (warmer leads to higher and vice versa).

When you read about reaching "full potential" it is usually in the context of the existence of either cloud layers that may inhibit solar heating of the surface, or the existence of a low-level temperature inversion, or in many cases some combination of both. Because we often start the day with some degree of temperature inversion, there is often a rapid warmup through the morning until that fairly shallow layer of air is heated sufficiently to erase the inversion, then any further heating results in much deeper convective mixing of the air heated by contact with the surface. The deeper mixing brings cooler air down from above and slows the rate of temperature increase near the ground.

In the alternate scenarios you mentioned, it typically would be the case that, all else being equal, day-long sunshine would result in a warmer afternoon high compared to, say, cloudy skies until early afternoon and then clearing, but it is also the case that in many instances, all but a few degrees of the difference can be made up in a few hours of sunshine. Essentially, the cloud cover earlier resulted in delaying the rapid portion of the days heating until afternoon. The "arbitrary height" you mentioned is actually a stand-in for the maximum temperature that could have been realized with all-day sun, since that height is representative of the intrinsic warmth of the airmass over a deep layer.
May. 29, 2014 | Tags: general meteorology

Question: Is it true that a tornado will not touch down at a location if it is currently raining there? — Laura

Answer: That is not a good assumption to make, as it is possible to have what are known as "rain wrapped" tornadoes that are heavily enshrouded in a curtain or shaft of rain. In addition, even in the case of a storm in which the tornado is exposed and located outside of an area where rain is reaching the ground, it is quite possible for that tornado to move across an area where rain was falling just minutes earlier.
May. 28, 2014 | Tags: folklore, preparedness, tornadoes

Question: Help.. How do I change my default weather view back to Raleigh? Last week I looked at Fayetteville and it is now defaulting to that location..? — P Godwin

Answer: On our main weather page, just type "Raleigh, NC" into the box that says "Enter zipcode or city," click the "change" button, and that will return you to the local default forecast. Assuming you are logged on to our site when you do that, it should show you the Raleigh forecast again the next time you visit the site.
May. 27, 2014 | Tags: wral.com

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