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Question: Did anyone report a meteor/fireball around 10:20 EST Saturday night, November 20? It moved south to north in the western sky,relatively slowly, and ended in a green fireball about half the size of the moon. So slow in fact that it could have been space debris. — David King

Answer: There were quite a few reports right in that time frame that are logged on the Fireball Reports section of the American Meteor Society web site. The address is
www.amsmeteors.org/members/imo_view/event/2016/4422, where you'll also find a "report a fireball" button at the top of the page in case you'd like to add your observations to the database. It seems likely this was a meteor, rather than a debris re-entry, unless it was an unpredicted re-entry not covered in the list at www.aerospace.org/cords/reentry-predictions/upcoming-reentries-2-2/.


Nov. 16, 2016 | Tags: astronomy, cool sites

Question: Could the Triangle be seeing a drier, warmer winter this year? — Stephen

Answer: There are some conflicting signals that make any confidence about how our winter will play out difficult to come by. It appears the Pacific favors a weak to near-neutral La Nina lingering into and through the coming winter. This weakly correlates to a higher than normal chance of drier than normal conditions for our area, as well as warmer than normal conditions, along the lines of what you noted in your question, but historically there is a good deal of variability in how winters turn out from one La Nina season to another. A different climate signal that has been in the news recently is the extent of Eurasian snow cover at the end of October, which has been linked to frequent cold outbreaks across the northeastern half or so of the USA, especially in the area of the Great Lakes and the northeast. This could be an indicator of some notable cold air outbreaks, though it doesn't do much to help determine whether we will happen to have significant precipitation during those episodes. We ran a very simple correlation of Eurasian snow cover versus seasonal snowfall, mean seasonal temperature and the number of days with an inch or more of snow at the Raleigh-Durham airport. The resulting correlation values suggested very little if any systematic relationship between October Eurasian snow extent and seasonal snow at RDU, a very weak correlation between greater snow cover there and cooler mean winter temperatures at RDU, and a small but positive correlation between that snow extent and the number of days an inch or more of snow occurred at RDU. Taken together, all that means we can't make any real definitive statement about how winter is likely to turn out.
Nov. 15, 2016 | Tags: el nino/la nina, normals, winter weather

Question: I have a question about the cumulative rainfall amounts. Does being nearer the center of the city affect the rainfall? For example, the RDU rainfall shows little rain since Matthew, and that is what we have here. However, before that, from 8/15 - 10/10, it shows somewhat below average but a reasonable ratcheting up. However, where I live, about a mile south of I 540 north, we had only a few sprinkles in that time and I barely had to cut my grass. Right now, it looks like my azaleas are under significant stress and may not make it, something I would not really expect for a cumulative rainfall that is above normal. — Margaret

Answer: The cumulative total graphs on our web site show the values specifically for the RDU airport. While these often even out reasonably well for the surrounding region over time, for a few weeks or a few months it is quite possible for amounts to vary a good deal over fairly short distances. Looking over radar and gauge based estimates for the general area around the airport does make it appear pretty substantial rainfall fell in most places during a number of periods through August and September. As you noted, since the very heavy rains of Matthew ended there have only been 2-3 additional episodes with rainfall, each of which were quite light and scattered. That has left what was initially very wet topsoil and subsoil values across the region on the decline. By the time you wrote to ask, crop soil moisture readings were down to the "slightly dry to favorably moist category" and evaporation rates had notably exceeded precipitation rates in recent weeks. With the uppermost soil levels drying at varying rates across the area, it seems possible your azaleas are responding to a short-term lack of water, though we can't really address whether some other factor may be affecting your particular plants.
Nov. 14, 2016 | Tags: rain, wral.com

Question: Is there any indication of any cold weather coming in November? — Dennis R. Sheppard

Answer: Compared to the warm excursions we experienced early in the month and in late October, temperatures appear they will remain more seasonable, perhaps including some short stretches of below-normal readings, through the second half or so of the month. So far, though, there haven't been detectable signs of an extended period of unusually cold weather developing in the next few weeks. As always, it's worth noting that projections beyond the next several days to a week or so involve a good deal of uncertainty and are subject to change.
Nov. 13, 2016 | Tags: cold

Question: Just a statement... Sunday AM 11/6 my husband had a small amount of water in the bed of his truck and it was frozen. We live at Keener. Small community between Clinton and Newton Grove along 701. — Pat West

Answer: That's a great illustration of how surfaces exposed to open sky on cold, clear nights can become colder than the air just a few feet above where temperatures are typically measured and reported. This can lead to frost on mornings when air temperatures are several degrees above freezing. In your case, the Clinton airport and a nearby personal weather station not far west of Newton Grove showed minimum air temperatures of 37 and 36 degrees F, respectively. The bed of your husband's truck clearly cooled by radiative heat loss to at least 32 degrees, and maybe a degree or two colder, leading the water in it to become ice.
Nov. 12, 2016 | Tags: cold, general meteorology

Question: When can we expect our first frost? — Jeremy

Answer: A lot of our area has already had some frost by the time you see this, as we had a couple of episodes in late October and early November with scattered frost, mainly in outlying, sheltered and typically colder locations. Then a more widespread frost, with some pockets of freezing air temperatures as well (including upper 20s around Siler City and Sanford), occurred the morning of Election Day. At RDU that morning, the low temperature didn't quite reach freezing, but did briefly dip to 33 degrees. It appears possible the first freezing temperature of the year will occur there this weekend, but that remains subject to change. The "normal" first freeze date for RDU is October 31st, but a good deal of variability is possible from year to year, and we've had a first freeze there as late as November 28th.
Nov. 11, 2016 | Tags: cold, dew/frost, records/extremes

Question: I was a five-year-old boy when hurricane Hazel hit North Carolina. My family and I lived about a mile east of Wilbur's BBQ in Goldsboro, and I remember walking around checking storm damage with my father and grandfather during the eye of the storm. However, all of the Hazel tracking maps I find show the storm center passing west of Goldsboro. Is my memory faulty, was the eye of the storm that large, or are the maps wrong? — John Daniels

Answer: It's tough to answer with certainty on this, but based on the official track of the center of circulation and the forward speed of Hazel as it passed through our state (around 55 mph, with the center, as you noted, tracking north-northeast just a little closer to Raleigh than to Goldsboro), we suspect you either got out during a very brief lull at the time the center was nearest your location, which still would have been a dicey proposition as far east as your location, or else you may instead be remembering heading out to look around after the storm had moved away to the north. From landfall near the SC/NC border to moving out of our state in northern Warren County only took about 4 hours, and in two more hours the center had shot all the way up near Harrisburg, PA. For anyone else interested in seeing Hazel's track in detail, a good resource is available at coast.noaa.gov/hurricanes/. There's also a nice summary of Hazel's impacts on NC at www4.ncsu.edu/~nwsfo/storage/cases/19541015/.
Nov. 10, 2016 | Tags: cool sites, hurricanes, past weather

Question: What were the primary factors (wind, total rain, rain intensity) that brought down trees in the Raleigh area during Hurricane Matthew? Are there any weather sites that showed rainfall amounts during shorter periods than 24 hours during the effects of this event in Raleigh area? I'll take 24 hour totals if that is only thing available. — Dave Crotts

Answer: It's a little difficult to separate the factors you noted for the Triangle area, where top wind gusts ranged on the order of 40-50 mph. Over a brief period of time, those kind of peak winds don't tend to take down many trees, but with frequent gusts over a period of time, together with heavy rain (around 4-9" for the Triangle) that both rapidly saturated the soil and coated the leaves and bark to make the trees a little more top-heavy, and given that most leaves were still on (adding to the surface area acted on by the strong winds), a good number of trees were toppled. Both rain amounts and wind gusts were somewhat higher to the south and southeast of the Triangle.

You can see a map of peak gust values at www4.ncsu.edu/~nwsfo/storage/cases/20161008/windgust.20161008.png, and Matthew-related precipitation at www4.ncsu.edu/~nwsfo/storage/cases/20161008/precip.20161008.png.

As for seeing rainfall amounts over shorter periods, you should be able to find hourly amounts for airport stations using the "Almanac" section of our web site. Go to the "Get Historical Data" area and choose the date the storm moved in. When you click send you'll got to a page with hourly observations from RDU at the bottom of the page. there is also a section along the right side of the page that you can use to switch sites and view data from other cities around the area.



Nov. 9, 2016 | Tags: hurricanes, past weather, rain, winds, wral.com

Question: Can you please tell me when the temps are going to start to stay cooler and colder than they are now? These warm temps are not my liking. I like the fall, but especially the winter. — Beth

Answer: At the time you wrote in, we were still headed for a couple of excursions into the 80s as we finished out October and started November, but most indications for mid to longer ranges after that were for a return to more typical temperature ranges for mid and late November (albeit with some variability), and just a weak tilt of the odds for December toward an overall warmer than normal month. Do note that climate influence signals are fairly weak at this time, so longer range outlooks of these sorts are fairly low in confidence.
Nov. 8, 2016 | Tags: general meteorology

Question: Will we have another unseasonably warm end of November and December like last year? — Mark Womack

Answer: There isn't a very strong influencing climate signal to base a confident forecast about that on, though a weak La Nina pattern in the Pacific does suggest a slight tilt of odds toward warmer and drier than normal weather overall for December into January. In the shorter term, most models lean toward a range of temperatures not too far off normal for the most part as we head through the first half or so of November (after a rather warm start in the first few days of the month), while the Climate Prediction Center suggests the latter half of November has about equal chances of turning out above, near, or below normal for temperatures.
Nov. 7, 2016 | Tags: fronts & airmasses

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