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Recent Questions

Question: On your weather feed, you showed some statistics about normal and record highs recently. When were these stats started to be kept? Where can I find them? — Dan

Answer: Those numbers were for Raleigh, as you noted - currently, the official numbers come from the RDU airport (and have since 1944). We use a database search tool called ACIS (Applied Climate Information System) that is readily available online, and usually select the "Raleigh Area" data in that tool rather than the "Raleigh-Durham" (RDU) selection. This uses an extended database that concatenates information from all of the "official" sites for Raleigh going back to 1887. Here's the address...

Aug. 10, 2016 | Tags: cool sites, past weather, records/extremes

Question: I live in The Villages, Florida and it appears that weather, particularly thunderstorms, tend to go around the Villages. We don't get as much rain as the surrounding area. I am told that radiation from the roofs of 50000 closely packed homes can affect weather patterns. — Barry Connell

Answer: It's certainly the case that the character of the surface can impact the lower atmosphere and therefore weather patterns in any given location, especially in the way of microclimates. However, it can be difficult to attribute something like the sense of storms going around a given location to a particular cause without a very detailed investigation. More commonly, there is a perception that storms often go around any given point because of the frequently scattered distribution of thunderstorm cells and clusters, their rapid variability in terms of size and intensity, and the tendency for radar depictions of those storms to make them appear to cover more area than they really do. We find here in central North Carolina, that people from almost every part of our viewing area perceive that storms preferentially split or dissipate when approaching their location, and reform farther downstream. We did note than in the Florida peninsula, there is a drier axis that stretches from a little north of your location all the way to the southern end of the state, with higher average rainfall closer tot he coasts to either side. We suspect this is a reflection of thunderstorms that often form along the sea breeze, progress inland and deplete some of their initial moisture and energy before reaching the interior sections of the state. For someone centrally located like yourself, this could result in a number of times when storms approaching from either the east or west would diminish in coverage before arriving.
Aug. 9, 2016 | Tags: folklore, general meteorology, thunderstorms

Question: What is the largest margin between the actual temperature and corresponding heat index we've experienced? — Sandra

Answer: Interesting question. We turned to our friends at the State Climate Office for some assistance in running a database search to calculate hourly heat index values from the RDU airport and look for the largest such spread. We suspected it would occur in conjunction with the highest reported dew point reading at the airport, which was 82 degrees on August 10, 2007, since the highest dew point corresponds to the most moisture in the air. It turned out that did in fact result in the largest spread between temperature, which was 89 at the time, and the heat index, which was 108 degrees, for a 19 degree margin. There's a tie for second highest, at 18 degrees, which occurred on both June 27, 1978 and July 21, 1981 - on each of those days, there was a point at which the temperature 92 and the dew point 80, for a heat index of 110 degrees.
Aug. 8, 2016 | Tags: apparent temperature, humidity/dew point, records/extremes

Question: How is ambient temperature measured? Is it in the sun or in the shade? Since both influence the thermometer, how do we know the temperature? — Chuck

Answer: Ideally, the "surface" temperature is measured about 2 meters off the ground, in an open area with a grassy surface, well away from trees or buildings. The sensor should be in an area that isn't shaded, but the thermometer itself is housed in a light-colored ventilated enclosure so that it isn't exposed to direct sunlight in the daytime or to open sky at night. This allows the thermometer to measure the temperature of the air passing through the enclosure itself, without reading too high in the daytime because of solar energy being directly absorbed by the sensor, or too low at night because of infrared radiation leaving the sensor and causing it to become cooler than the surrounding air. Some official thermometer installations are "aspirated," meaning there is a fan that ensures outside air continually flows into and through the enclosure, even when ambient winds are calm or very light.
Aug. 7, 2016 | Tags: general meteorology, instruments

Question: Humidity is so important to how one feels in high heat. And high humidity with high heat can certainly cause health issues. Why is humidity not listed more prominently on the website (forecasts, current conditions, etc?) We get the temp and possibility of rain... why no humidity? — Greg Schneck

Answer: We agree that humidity levels play an important role in comfort, and potentially health and safety, when temperatures are on the hot side. For that reason, the write-ups in our seven day forecast will often mention humidity and/or expected heat index levels when those are of special interest. In addition, we certainly don't try to make it hard to find current and projected humidity values (and especially dew point, since that value is more directly proportional to how much moisture is in the air than is relative humidity). You'll find both of those displayed rather prominently when you click on our "Current Conditions" link, and likewise, if you click on the "Hourly" link you'll have access to a lot of info on humidity. First, there is a graph toward the bottom of the page that includes selections for humidity, dew point and "feels like" which is set to show heat index in hot weather, and wind chill when it's cold. Finally, in the hourly forecast, you'll see a "more details" link - clicking that link will show you projected dew point and relative humidity values every hour, along with the sky condition, rain chance, wind, etc.
Aug. 6, 2016 | Tags: humidity/dew point, weather & health,

Question: I saw a local grocery store has their bee hive exposed to full sun in this hot weather. Should not they move the bee hive to shaded area? I Am afraid bees may suffer or die since the temperature of the hive could be extremely high. — Y C Lee

Answer: That was a good thought to bring up, given the run of mid 90s temperatures and high humidity we were having when you wrote in. We did some checking on recommendations regarding hives and exposure to direct sun, and the general consensus was that bees are probably safe and will remain healthy despite direct sun and hot temperatures, though they may tend to expend more energy cooling the hive and thus be less productive in other ways during the hottest part of the day. Some beekeepers seem to favor, where possible, siting their hives in locations that will receive direct sunlight early in the day (prompting the bees to become active earlier) and will be shaded during the afternoon (allowing them to expend less effort cooling the hive, and leaving more energy for active foraging and honey production).
Aug. 5, 2016 | Tags: heat, weather & health

Question: What was the high temperature on July 28 officially at the RDU airport and in Clayton, plus what were the heat indices? — Deb Jones

Answer: Observations from Thursday July 28, 2016 from RDU show a maximum temperature of 96 degrees, with a top heat index value of 109. We also checked data from two stations in Clayton for that day, and found the respective highs were 98 and 97, with maximum heat index values of 106 and 104.
Aug. 4, 2016 | Tags: apparent temperature, heat, past weather

Question: In terms of circulation size or cloud canopy which one of these storms was the biggest.. Sandy or Super Typhoon Tip? — David

Answer: We weren't able to find comparable measurements of cloud area, but both systems were tracked with regard to the diameter of tropical storm force winds. While Sandy set the Atlantic record in that respect, with a circulation diameter of roughly 1000 miles, Typhoon Tip retains the global record by that measure, with a diameter of about 1350 miles. Until 2015, Tip was also known for the strongest maximum sustained winds in a tropical cyclone, at 190 mph. However, it was surpassed by eastern Pacific Hurricane Patricia's 215 mph peak sustained winds that season.
Aug. 3, 2016 | Tags: hurricanes, records/extremes

Question: In Holly Springs on Tuesday evening July 26th at 8:35 PM, we'd had rain, thunder and lightning, including one that sounded like a local strike for about half an hour with no warnings. Now that the power has gone off and on we are getting the notices online but not on the phone. Any idea why? I trust your team implicitly for weather notifications and warnings but this one seems to have slipped through the cracks. — Doris E Bornkessel

Answer: We reviewed radar and warning archives from that evening, and found that based on the time you sent your message and the location outlines of the warnings that were issued for the slow-moving storm that was drifting across the area then. We found that an initial severe thunderstorm warning was issued for western Wake County at 8:06 PM, but the boundary of that warning was just northwest of Holly Springs. As the storm spread a little more intensely east and southeast, an updated, expanded warning area was issued at 8:45 PM. That one did included Holly Springs. While the storm produced a terrific amount of lightning, some rainfall totals on the order of 1-2 inches and gusty winds, reported damage was limited to trees down in a couple of isolated locations.
Aug. 2, 2016 | Tags: past weather, severe weather,

Question: How long is this excessive heatwave (temps above 95) going to be in NC? — Brandon

Answer: You sent your question midway through the stretch of above-normal heat, and at the time we are writing this answer, it appears the heat will begin to abate, at least temporarily, by the time you read it. While it will remain seasonably warm and humid, the mid and upper 90s highs should be running more on the order of mid 80s to low 90s as we kick off August, perhaps edging back up somewhat late in the week. This is a very general outlook from a few days before the answer posts on our web site, so we'd refer you to the current 7-day forecast for the latest information.
Aug. 1, 2016 | Tags: heat,

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