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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Question: Is it just me or is it always RAINY or cloudy on Christmas day? I can't remember the last time it was bright and sunny on December 25. Could it happen this year? — Gerald
Answer: It isn't always by any means, but there can be "streakiness" in the behavior of weather and climate, and we have had a streak of cloudier, rainier Christmas Days in the Raleigh area over the past ten years, which probably accounts for your perception. In the long term, a December day has about a 45% chance of being mostly cloudy or cloudy, but 70% of the last ten Christmases have met that criteria here. About 32% of December days would rate as mostly sunny to sunny, but only one Christmas (10%) has done so since 2003. In terms of measurable precipitation, about 29% of December days manage that, but of the last 10 Christmases, six (60%) have featured measurable rain and in one case (2010) some snow as well. We're a few weeks from the next Christmas as we write this answer, so it's too far away to know what kind of cloud cover and precipitation chances we'll have then.
Dec. 7, 2013 | Tags: clouds, normals, past weather
Question: Why have you dropped Roanoke Rapids from your weather map? — Calvin Potter
Answer: We're not certain which map you're referring to, but we use several different maps with different areas included. None of them can contain every city or town name in our viewing area, so we mix them up a bit. We definitely include Roanoke Rapids on some of them. As with other towns, there are occasions when the automated FAA/NWS reporting systems that send in temperatures and other weather data are offline for one reason or another. In these cases, there may be a period of time when that town doesn't appear so that we avoid having a blank data box on the map.
Dec. 6, 2013 | Tags: maps & codes
Question: We had light snow flurries one day in the last two weeks; what day was that? — Henry
Answer: You're thinking of Tuesday, Nov 12, 2013, when a cold front and strong upper level disturbance combined to cause temperatures to plunge from 61 degrees around lunchtime to mid 30s by 6 PM, with rain changing over to patchy light snow. For most areas where it occurred, the snow didn't reach measurable levels and was recorded as a trace.
Dec. 5, 2013 | Tags: past weather, snow
Question: I left Raleigh on January 1st, 2002, with a lot of snow on the ground; I'm back now (missed your weather forecasts); how many inches of snow fell on that day? — Gary Lee
Answer: That was a big snowstorm for much of central and eastern North Carolina. It actually began snowing at the Raleigh-Durham airport around 6:30 PM on January 2nd and continued to snow most of the time until after 8:00 PM the following days. RDU recorded 10.8 inches of snow for the entire storm, while much of the surrounding area received anywhere from 10-14 inches. You can see a contour map of snow totals for the storm, along with some radar and satellite maps, at www4.ncsu.edu/~nwsfo/storage/cases/20020102/.
Dec. 4, 2013 | Tags: cool sites, past weather, snow
Question: Once the 'start' button is pushed, how long does it take a European or GFS model to run? Are specialty models run for hurricanes or winter storms? — Chris
Answer: To some extent, this is an oversimplification, since there is some almost continuous assimilation of new data and adjustment to initial conditions for a new model run that are based both on fields predicted by a previous model run and new observed data. That said, for the Global Forecast System (GFS) produced by the U.S. National Centers for Environmental Prediction, the time from a primary new data dump to the finish of a 384-hour forecast cycle is about an hour and 25 minutes. That includes about 1:10 from the forecast start time to completion of the higher resolution part of the process (out to 180 hours) and another 15 to complete a lower resolution portion out to hour 384. A follow-on ensemble run, repeating 21 runs of a lower resolution version of the model with perturbed intitial conditions, takes about an hour and 20 minutes and finishes around an hour and ten minutes after the main model.
We don't have the exact corresponding schedule info for the European model, but understand the main hi-resolution calculations for it take about an hour and ten minutes for a forecast out to 240 hours in the future.
There are a variety of hurricane specialty models run by different organizations, in addition to some other higher-resolution regional models that may be of special interest for severe weather, winters storms and so on.
For the basic production schedule of the GFS and other primary model suites the NCEP produces, you can check the latest schedule at www.nco.ncep.noaa.gov/pmb/nwprod/prodstat_new/.
Dec. 3, 2013 | Tags: cool sites, instruments, maps & codes
Question: Why is the sun so bright today? It was blinding this morning and it's still blinding this afternoon. It's not golden looking at all, but like a bright white fireball. — Joanne Brady
Answer: Usually, that perception of the sun being especially bright is driven in relation to a period of preceding days that featured either a lot of clouds or comparatively humid and hazy conditions that mute the sunlight somewhat. A peek at weather observations leading up to the date of your question seems to fit this pattern, as at least some rain was reported each of the preceding three days, with dew points in the 50s and 60s and some periods of limited visibility. Then, on the day you wrote, we had a much drier airmass in place with mostly sunny skies. The lack of clouds, haze, pollutant particles, humidity and fog made the sun seem brighter, and probably made everything appear sharper and more vivid. The sun's yellowish color as we see it is due to it's light passing through the atmosphere, which scatters some of the blue and green color off to the sides. This effect is greater when there is more water vapor, haze and pollution in the air, so when those factors are minimized in the wake of an airmass change, it may appear a little bit whiter.
Dec. 2, 2013 | Tags: astronomy, atmospheric optics, past weather
Question: I see a lot when it's very cold and it just sleets rather than snows, but then I also see it sleet when it's not quite cold enough to snow. What is the difference between the conditions that make sleet, snow, and freezing rain occur? — Adam
Answer: The most basic factor controlling the kind of precipitation that reaches the ground is the way temperature varies as you move from high in the atmosphere down toward the ground. If there is enough moisture in a layer of the atmosphere with temperatures in the right range to form snow crystals, which is quite common through the colder half of the year, then those snow crystals (and when some clump together, snowflakes) can fall all the way to the surface if the air is near or below freezing all the way down, or if any layers that are above freezing are rather shallow so that the flakes do not have time to melt. If there is a layer along the way that is warm enough to melt the flakes, they become rain drops. If the air is mostly above freezing the rest of the way to the surface, they will reach the ground as rain. If they fall through another layer of air that is below freezing, however, and it is deep enough, they will freeze into clear ice pellets before reaching the ground. Finally, if they fall through only a shallow layer at ground level that is below or near freezing, they may arrive at the ground as liquid droplets that can spread out and then freeze when they encounter freezing or sub-freezing objects at the surface. This is the condition for freezing rain, which can lead to the formation of a clear glaze of ice.
Dec. 1, 2013 | Tags: general meteorology, snow, winter weather
Question: Is it true that all places on earth receive the same hours of daylight and nighttime each year? The equator is 50/50 and at the poles there are totally dark and totally bright days but it all should average out. What do you think? Do I just have too much time on my hands. — Andrew Barrett
Answer: We would come pretty close to that if the earth followed a circular rather than slightly elliptical orbit, and if there was no atmospheric refraction, which is a bending of the light from the sun that makes it appear higher in the sky than it really is when it at rather low altitudes, with the greatest effect near the times of sunrise and sunset. This effect leads to more hours of daylight than darkness, because we can still see it above the horizon when it is actually below the horizon and would appear so in the absence of an atmosphere. Also, over the course of a year, the sun is near the horizon, and thus most subject to refraction making it appear higher, more often near the Arctic and Antarctic circles than at lower and higher latitudes. The result is these latitudes have a peak of annual daylight hours that is higher than other locations. Further, because of the elliptical orbit around the sun, the Arctic Circle averages more daylight hours than does its southern counterpart.
Note that this all refers to hours of sunlight and not to intensity, which is much greater at lower latitudes due to the sunlight striking the ground at a much more direct angle since the sun is much higher in the sky.
Nov. 30, 2013 | Tags: astronomy
Question: I live in S. Durham near where hwy 55 and 54 intersect. What time is "high-noon" here? And besides the change to and from day-light time, does this time vary? If so, how much? — Bradley Hastings
Answer: We assume that by "high noon" you are asking about the time of solar noon, when the sun would reach its highest point in the southern sky and transition from being southeast of your location to being southwest (at our latitude the sun is never directly overhead).
The time that occurs relative to a clock varies because of the tilt of the earth's axis and its slightly non-circular orbit. For more on that variation, which covers around a thirty minute spread, do a web search for "equation of time."
Finally, to see what time that transit occurs, you can go to a nice page operated by the U.S. Naval Observatory. We have a link to that site's "Sun and Moon Data" on our Almanac page. Choosing a date and entering your state and city will provide sunrise, sunset, transit, twilight and moonrise/set times.
Nov. 29, 2013 | Tags: astronomy, cool sites
Question: How do I find out what the weather was like in a certain US city the first week of November, 2013? Prefer a free service. Thank you. — M Bryan
Answer: You can go through our Almanac page, where you'll find a "Get Historical Data" section. Just choose the date that starts the period you're interested in, and you will be taken to a page with observed data from the RDU airport for that date, including a table of hourly observations at the bottom of the page. Along the right side of that page is a "Weather History Location" box where you can enter any airport code and retrieve the same kind of data for that location. You can also use a tab near the top of the page to switch between daily, weekly or monthly overviews of the data. There is no charge to use the database, which is provided by Weather Underground.
Nov. 28, 2013 | Tags: cool sites, past weather, wral.com
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Published: 2007-10-09 14:40:00
Updated: 2013-08-13 13:37:27
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