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Recent Questions

Question: Why were the county outlines removed from the state radar map? It is much more difficult to track the exact location of a line of storms without the outlines. — Mack Hilliard

Answer: In the process of changing the online maps to reflect the new graphics system we began using on-air recently, the zoom level that triggered county lines to appear on that map was set a little differently and resulted in only state borders appearing on the "North Carolina" view of the regional composite radar display. We agree with you that the county borders at that scale make it easier to gauge the location and movement of radar echoes, and we've already implemented a change that addresses the issue (this refers to the map that appears when you go to the "DualDoppler 5000" page, and change the selection to "Radar" using the blue buttons above the image). Thanks for contacting us about that!
May. 16, 2017 | Tags: maps & codes, weather radar, wral.com

Question: Where can I find the map that showed the damage from the storm (blue diamonds & red triangles)? — Steven

Answer: The "Storm Reports" map from our TV broadcasts you're referring to is one we post on an as-needed basis when the region has been affected by severe weather, sometimes as part of a weather story or as an item in our Weather feed section. As you noted, it usually shows reports with blue diamonds for wind damage, red triangles for tornado reports and also green circles for hail equal to or greater than 1-inch in diameter. We also maintain a page where you can see an interactive storm reports map using the same symbols, archived to make the past 7-days of reports available. The address for that is www.wral.com/weather/page/1010362/ (or from our main page, click on "Alert Center" and then the "Active Alerts" box, and finally the link in the line that begins "View local and national..."), and when you select a day that has some report symbols on the map, you can click on individual symbols to see the text report showing when and where it occurred, along with the description that was provided by a spotter and/or the NWS. Finally, if you miss some reports that have moved beyond the 7-day archive window we maintain here, you can look much further back in time for similar information through the Storm Prediction Center storm reports page at www.spc.noaa.gov/climo/online/ (note the "Past Storm Reports" section) or from the State Climate Office of NC, at climate.ncsu.edu/lsrdb/index.php.
May. 15, 2017 | Tags: cool sites, maps & codes, past weather, severe weather, wral.com

Question: In the Sanford area what was the amount of rainfall on Monday night, May 1st? Also, what was the speed of wind gusts for the same day and area? — Joe Russell

Answer: For rainfall in that period, we checked observations from the Sanford-Lee County airport and also radar rain estimates for the surrounding area. The airport recorded .19 inches of rain, with radar indicating a general range of about 1-3 tenths of an inch across the county. Winds were gusty in the afternoon and evening, with the top gust at the Sanford airport reaching 30 mph, but some nearby locations recorded gusts as high as 35-40 mph. In addition, there were quite a few reports of thunderstorm gusts strong enough to bring down trees just to the west, although that band of storms tended to weaken by the time it moved east of about Randolph County. To see a Storm Prediction Center map of reported high wind damage from the afternoon and evening leading into that Monday night, see www.spc.noaa.gov/climo/reports/170501_rpts.html.
May. 14, 2017 | Tags: cool sites, past weather, rain, severe weather, winds

Question: I apologize if you have answered this question before but in the cold front passage earlier this week (today is May 5) and the one occurring today, all of the public forecasts show dew points falling but wind continuing to come out of the SW or W. I thought most of our cold fronts came from either NW or NE (back door front). Why would a SW flow not be bringing up warm humid air? — Dave Crotts

Answer: Like many aspects of meteorology, there are typical and common situations, such as the most frequent types of cold frontal passages that you mentioned, and there are complications and exceptions to rules. One that occurs from time to time is the situation you noticed in which a frontal passage, usually accompanied by a low pressure area that intensifies some not too far to our north or northwest as it passes, produces a west or southwesterly flow in the wake of the frontal, but drier and sometimes cooler air that is associated with the front has been pushed a long way south over the nation's midsection or along the Mississippi Valley, before being transported into our state from the west. This can allow even air from the southwest to move in with lower dew points (and thus humidity) than the air it replaces. In many of these cases, the air coming in from the west or southwest is notably drier than the air ahead of the front, but not much cooler, and in some of these cases we actually warm up more in the immediate aftermath of the "cold" front, simply due to a lack of precipitation and much more sunshine once the front has pushed away to the east.
May. 13, 2017 | Tags: fronts & airmasses, general meteorology

Question: What are the best places in CONUS to view totality of the August 21 eclipse with clear skies? — Kirk Proctor

Answer: Of course, this far in advance we have to turn to climatology and average conditions rather than specific forecasts, but in general the lowest average cloud cover around the time of day of the eclipse along its patch of totality stretches from interior Oregon to the central Plains, with somewhat higher average cloud cover from the Mississippi River Basin east. It's worth noting, though, that over much of the Carolinas August afternoon cloud cover is typically dominated by cumuliform clouds driven by upward motions induced by solar heating, and that in similar situations cumulus cloud cover often abates considerably during the gradual cooling that occurs as the moon covers more and more of the sun. For much more information and a wealth of resources related to weather and the eclipse, check out the National Overview and regional discussion links at eclipsophile.com/overview/, and also take note of the "WeatherDesk 2017" menu item near the top of the page. Additional details about the eclipse itself are available at eclipse2017.nasa.gov/eclipse-who-what-where-when-and-how and at www.mreclipse.com/.
May. 12, 2017 | Tags: astronomy, clouds, normals

Question: Could the answer to Nadine's question referring to flooding along the Tar as well as other rivers, be attributed to the explosive growth of the Triangle from new roads, house construction, etc, causing major runoff into our streams and river basins? — Frank

Answer: The factors you mentioned involving increases in impervious surfaces that lead to greater runoff rates in heavy rainfall events are important to consider and have certainly played a role in how streams and rivers respond to these situations, and how that response evolves over time, so you raise a good point. However, we think it is unlikely that changes during the 6 months between Matthew and the April storm were enough to have a strongly noticeable added impact, while the localized differences and similarities in amount and distribution of rain between the two events seems to reasonably account for the differences in flooding levels that resulted.
May. 11, 2017 | Tags: flooding, lakes and rivers, rain

Question: If the hourly forecast is 0% chance of precipitation and it is raining, does that make the forecast 100% wrong? — David Buffaloe

Answer: It's certainly hard to argue otherwise, although the converse isn't necessarily true. Ideally, we try to reserve the use of a zero percent rain chance to days we're very confident of dry weather for the great majority if not all of our viewing area. However, in order to allow for some variation across the region and to allow for tailored forecasts for specific towns or zip codes, etc, including anywhere in the U.S., our hourly forecast info is automated and tied to a gridded forecast database that is strongly influenced by computer model projections. Because these occasionally show a zero percent chance when we would probably lean more toward something in the 10-20% range, we encourage you to use the hourly forecasts in conjunction with the parts of our web site that include our written description of the forecast along with a daytime or nighttime probability of precipitation that we select and enter directly. That will often give you a better sense of whether we think a few isolated showers are not out of the question, even if an automated hourly forecast shows 0 percent for some portion of the day. On the other hand, a 100% chance of rain for a given valid period (whether an hour or a day, for example) wouldn't be wrong simply because rain isn't falling at a given moment, but would be wrong if the entire hour or day went by with no measurable precipitation. It means that precipitation is definitely expected to occur within the valid time of the forecast, but not every minute of that forecast period.
May. 10, 2017 | Tags: maps & codes, rain, wral.com

Question: Could you folks put the date on your maps? I record a lot of shows which include the weather, but I have no idea what day it was for. — Dana

Answer: It's doubtful we'll be doing that due to the potential for adding too many pieces of information to graphics that are already pretty full, especially when you consider that there are also other pieces of information and "bugs" that are on the lower part of the screen in addition to our weather maps in many places. That said, there are usually some indicators of the day or date included visually (on the 7 day forecast, for example) or verbally, and during the surrounding news stories, that might help you. In addition, most recording devices that store recorded shows will include a time/date stamp for the recording that you can check before playing it back.
May. 9, 2017 | Tags: maps & codes

Question: Has the Raleigh Spring 2017 been abnormally windy so far this year -- or is it just me? — Wayne Buehrer

Answer: Taking "spring" as the meteorological version, meaning (so far) March and April, we have had enough windy periods that the average wind speed at RDU for March and April are both above the long-term average value, but just a little bit for March (7.9 mph versus the historical average of 7.8) and somewhat more for April (8.5 mph versus the average of 7.9). We haven't had new records for either month in terms of the highest observed winds during each month. The peak gust observed at RDU in March was 44 mph, compared to a record of 61 mph in 1999, while for April we had a gust as high as 52 mph, compared to a record of 59 from 2013.
May. 8, 2017 | Tags: normals, past weather, records/extremes, winds

Question: On your 4/28 broadcast you mentioned the low not going below 70 in the first 3 months of the year hadn't happened since the 1920s. That got me to wondering how reliable are records from early last century. How accurate was the measuring and recording equipment used then? Were temperature readings manual, and if so, how can we be sure that someone actually went out to read the temperature, especially on the cold winter nights. — Chuck

Answer: You raise good points, but for locations like Raleigh where observations were given a lot of importance, by the late 1800s instruments were reasonably accurate and reasonable care was taken to site them in shelters that would reduce biases due to radiative heating or heat loss. When it comes to reading the highest and lowest temperatures each day, a version of the minimum/maximum thermometer, initially developed in the late 1700s, was generally used. This meant that at most sites in the late 1800s and early 1900s, observations were taken once daily, usually in the late afternoon or early evening, at which time the max/min thermometer was "reset" in order to capture the high and low temperature that would occur within the following 24 hours. Note that this process did leave open the possibility of occasionally attributing a high or low to the wrong date when unusual variations of temperature occurred, but it did tend to capture rather well what the highest and lowest values were, so that noting the last time we had a low in the 70s in a given month was in 1925, that's a reasonably well-supported statistic given the techniques being used at the time.
May. 7, 2017 | Tags: instruments, maps & codes, past weather

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