WRAL.com: Raleigh, Durham, Fayetteville

The most direct way to find your question is to search for the name you used when you submitted it (first name, last name or both). If you did not include a name, then you can search using keywords from your question. Of course, since many weather-related terms are common to a lot of the questions we receive, this may turn up a number of others in addition to your own.

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Answer: For the Raleigh area, sunrise that morning will occur at about 7:02 AM EDT. For anyone who'd like to check the sunrise time for another location, there is a good source for that provided by the U.S. Naval Observatory. Just go to aa.usno.navy.mil/data/docs/RS_OneDay.php and select the date, along with the country, state and city or town you're interested in.
Mar. 25, 2013 | Tags: astronomy, cool sites

Answer: Gusts have many contributing factors, but the more routine gusts that we experience on days with moderate to strong winds derive largely from the passage of turbulent eddies that result from mechanical and thermal mixing. Winds flowing across topographical or man-made obstacles develop vortices and rolls that can alternately oppose (and weaken) or reinforce and add to the mean wind as they travel past a point leading to rapid surges and lulls in the wind. If a passing eddie or vortex happens to be stretched along its axis as it moves along, it's rotation speed will increase even more, adding to the strength of gusts it may produce. Similarly, thermals (bubbles of air heated by the surface that become buoyant and rise) lead to upward motion and compensating downward motion that can capture air with greater momentum from several hundred to several thousand feet above the ground, and transport it rapidly to the surface where it can produce sudden increases in wind speed.

A somewhat different mechanism can be involved in the production of severe gusts of wind from some thunderstorms, in which heavy precipitation in the storm can drag air from above downward at rather high speeds, spreading out and producing strong horizontal winds that oftent take on a gusty character. This process is sometimes enhanced if there are layers of dry air being entrained into parts of the storm, or a layer of relatively dry air below the cloud base. In these cases, the precipitation may partially evaporate, cooling the downward rushing air, making it denser and increasing its fall speed - this is often a factor in severe thunderstorm wind gusts.
Mar. 24, 2013 | Tags: general meteorology, severe weather, winds

Answer: In records going back to 1944 at RDU, the high temperature has been 20 degrees or colder 13 times. This includes two days, Jan 16, 1972 and Jan 21, 1985, with highs of 17 degrees. We also maxed out at 18 degrees there on Feb 17, 1958 and Jan 19, 1994.

In the last year or two, the local National Weather Service has produced a set of climate record data for the Raleigh area called ThreadEx that combines observations from several successive observing sites to run the start of the data set back to 1887. Checking that database, we find that the lowest high observed for the Raleigh area was 10 degrees on Feb 13, 1899. There were also observed highs of 13 degrees on Feb 12 that same year and 16 degrees on Dec 30, 1917.
Mar. 23, 2013 | Tags: cold, past weather, records/extremes

Answer: It turns out that more countries do not use DST than the other way around. Most "Western" nations in the northern hemisphere do apply the time shift, but overall a quick rough count shows about 77 countries or territories use a form of Daylight Saving Time, while about 168 do not. There are quite a few countries that have used it at some point in the past and no longer do, including Russia, China and a sizable portion of Central and South America. The Falkland Islands shifted to year-round DST starting in 2011.
Mar. 22, 2013 | Tags: maps & codes

Answer: Unfortunately, there isn't a good, specific way to forecast when the last frost will occur in a given season, but we can look at history for some guidance in regards to the last freeze date in the spring. It is also important to note that records are lacking for frost per se, due to the fact that frost can occur on surface objects even with measured air temperatures remaining above freezing. We have reliable records for last freeze dates, meaning those on which air temperatures fell to 32 degrees or below. The average last freeze date for the Raleigh-Durham airport is April 10th, but there is quite a bit of variability from year to year, such that there is still about a 20% chance of a freeze as late as April 17th and a 10% chance as late as April 23, with the latest freeze in 69 years of measurement coming on May 10th. These dates are about 9-10 days later than similar statistics for stations closer to or in Raleigh. Generally locations in central NC that are located in urban areas are closer to the those numbers, while those in more rural locations area closer to the numbers from RDU.
Mar. 21, 2013 | Tags: cold, dew/frost, normals, past weather

Answer: The storm you noted from January 10-11, 2011 left behind a coating of about .15-.25" of glaze ice from freezing rain around the Raleigh area. The system that affected the region on January 25, 2013 brought a mix of snow, sleet and freezing rain. Reports around the Raleigh area for that day included anywhere from .10-.15" of freezing rain glaze, along with .1-.3" of a sleet/snow mix.
Mar. 20, 2013 | Tags: past weather, winter weather

Answer: You can find those by clicking the "Almanac" link from our main weather page. Once you get to that page, you'll see a drop-down date selector labeled "get historical data." Just select the date you're interested in, click "go" and you'll open a page from the Weather Underground with observed conditions for the Raleigh-Durham airport for that day, and can easily step forward or backward a day at a time, or expand the listing to a week or month of observations. There is also the ability to switch to a different weather station if you're interested in readings from another part of the state or country.
Mar. 19, 2013 | Tags: past weather, wral.com

Answer: Moonrise for that evening was reported by the US Naval Observatory site to occur around 9:25 pm for our area, so you may have seen it a bit later, but the point to note was that you would have seen it just above the horizon at a time when it was about three days past full and still about 91% illuminated. When the moon is very near the horizon it's light is passing though a much greater distance of atmosphere than when it is at higher elevation angles. Since air molecules scatter short wavelengths (the blue end of the visible light spectrum) more strongly than long ones (the red end) you are left to see more of the red than blue portions of the original white light by the time it reaches your eyes. The amount of suspended pollutants in the atmosphere, in the form of smoke, dust or other particles, can also add to this effect, making it stronger on some occasions than others.

As for the "big" appearance, that is a perceptual artifact associated with seeing the moon (or sun) in close proximity to the horizon. It turns out that if you photograph the moon at that altitude and compare it with times when the moon is high in the sky, or you measure the angular size of the moon's disk using calipers, for example, you find that it is in fact no larger when it is near the horizon than when it is high above. For more on this, try a web search for "moon illusion."
Mar. 18, 2013 | Tags: astronomy, atmospheric optics

Answer: Climatological spring is a reference to the time of year when the sun angle has already increased significantly and average temperatures have climbed notably from their wintertime lows, so that periods of weather we consider "springlike" become more frequent, with the resulting responses from plant and animal life. It more specifically refers to the calendar months of March, April and May, used by meteorologists and climatologists for calculation of "spring" weather statistics, due in part to the changes in weather that have typically already taken place by March 1st, but also to the greater record-keeping convenience of not splitting seasons in the middle of calendar months. Hence for climate record-keeping we usually think of June-July_august and summer, September-October-November as fall and December-January-February as winter.

The more traditional definitions of the start of spring and the other seasons are tied to astronomical events associated with earth's position in its orbit around the sun. Spring is said to begin with the Vernal Equinox, summer with the Summer Solstice, fall with the Autumnal Equinox and winter with the Winter Solstice. The "climatological" seasons used by for weather records start about 3 weeks earlier and typically align a little more closely with the warmest and coldest average periods of the year (for summer and winter) and the intervening transition seasons.
Mar. 17, 2013 | Tags: astronomy, normals

Answer: Quite a few others did, as it turns out. You saw a meteor that was large and bright enough to be considered a "fireball." There are a number of reports of the event from observers in North Carolina and Virginia documented on the American Meteor Society's web site, in their 2013 fireball sightings log, that correspond almost exactly to your comments. You can see those reports at www.amsmeteors.org/fireball_event/2013/504.
Mar. 16, 2013 | Tags: astronomy