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Recent Questions

Question: I am heading to Junaluska in the Carolina mountains next week. Will CINDY have any effect on the weather there? — John McCanless

Answer: The system that had been Cindy did contribute a little to some shower and thunderstorm activity in the mountains, but it moved rather rapidly and along a somewhat northerly track, and given those circumstances it appears the mountains will end up with some very pleasant weather through a good part of your time there, with a fair amount of sunshine, very low rain chances, high temperatures in the 70s and humidity that is lower than average for this time of year.
Jun. 26, 2017 | Tags: humidity/dew point, lakes and rivers

Question: Could you please explain to me why it is always much cooler on March 21st than Sept 21st when the sun is in exactly the same position relative to the equator? — John Coleman

Answer: That's a good question, and the principal answer is that you are seeing the effects of where the sun has been for the months leading up to those dates more so than the exact positioning on the two equinoxes themselves (note that equinox dates vary a bit from year to year, and in 2017 the vernal equinox fell on March 20, while the autumnal will occur on September 22). At the RDU airport, the normal high temperature on March 21 is 65 degrees, while the mean dew point for the date is 40 degrees. On September 21, the normal high is 81 degrees and he mean dew point is 63. On both dates, the sun's position, together with refraction by the atmosphere and our definition of sunrise and sunset, results in about 12 hours and 8-9 minutes of sunlight. However, in the months leading up to March, the days are much shorter for a while, allowing for outgoing radiation at night to exceed incoming radiation for the day, and a gradual net cooling into midwinter, in addition to prompting changes in the upper level flow and average jet stream position that results in (typically) frequent intrusions of cold air from the north. This results in cold ground temperatures and cooling of oceans and other large bodies of water, which in turn results in lower amounts of water vapor in the air (hence the lower average dew point in March). Lower water vapor amounts allow for somewhat more efficient cooling by longwave radiation overnight. As we move through the summer, of course, the opposite happens, as longer days and short nights allow more heating of soils and water, which evaporates more moisture in to the air (in addition, considerable moisture is transpired into the air by much more abundant leaf, grass and plant cover through the summer and early fall). The combined effects of stored heat, and water vapor that somewhat limits loss of heat by radiative cooling at night, leads to the continued warmth of late September, and the overall lag of both heating and cooling leads to a much cooler equinox in March than in September. Some of the same factors also play a role in our warmest and coldest average temperatures being displaced a couple of weeks after the summer and winter solstices that mark the longest and shortest daylight periods of the year.
Jun. 25, 2017 | Tags: general meteorology, normals

Question: My husband and I take our morning walks along the "Mountain to the Sea" trail along the Neuse River. The last few days the river appears to be very low. Any idea as to why? — Janie McAdams

Answer: The Corps of Engineers regulates flow from the Falls Lake dam into the Neuse River downstream based on the amount of inflow to the lake from upstream, the elevation of the lake surface and the need for flow downstream from the lake. Starting around a week into June, flows into the lake became rather low and by around the 10th or 11th of the month, the lake level had fallen and outflow from the lake downstream was minimized, which likely led to the low river level you noticed not far downstream from the lake before sending in your question on June 16th. Conversely, very heavy rain upstream of the lake on the 19th into the 20th has sent inflows and the lake level sharply upward, and we suspect you may have seen, or will shortly, noticeably higher river levels due to increased releases from the lake. You can check on a variety of level, inflow, outflow and water temperature data for Falls Lake at epec.saw.usace.army.mil/fall.htm, and more generally for lakes in our region at epec.saw.usace.army.mil/index.asp.
Jun. 24, 2017 | Tags: cool sites, lakes and rivers, rain

Question: Why is the latest tropical system being referred to as a cyclone...anything in the Caribbean, Atlantic, and northern Pacific has always been referred to as a hurricane, tropical depression, tropical storm or system...we have never referred to our systems as cyclones...what's up with this latest system? — Julie Murphy

Answer: We've used the term "tropical cyclone" from time to time over the years, as it is a more generic means of referring to any of the terms you mentioned. For example, a tropical depression is a tropical cyclone with maximum sustained wind speeds of 38 mph or less, a hurricane is a tropical cyclone with maximum sustained winds of 74 mph or higher, and a tropical storm falls between those two on the wind speed scale. You've probably heard the term a little more often recently due to a new policy by the National Hurricane Center in which they can issue watches and warnings for tropical systems that have not formed yet. When they determine this is necessary, they will also issue graphical and text products showing the likely path, strength and impacts of the system that is forecast to develop. In these cases, they will refer to the storms as "Potential Tropical Cyclone" #, where "#" is a sequential number indicating the order of new storms through the season. So far this season, they have already issued advisories and forecast information packages for "Potential Tropical Cyclone Two," which became Tropical Storm Bret, and "... Three," which will likely become Cindy. They use the generic "cyclone" wording in these since they may not be confident ahead of time whether the system that develops will become only a depression, a storm or a hurricane, or may instead progress through all three stages.
Jun. 23, 2017 | Tags: hurricanes, maps & codes, preparedness

Question: I am heading about 45 minutes south of Cancun Mexico with my family from 6/24-7/1. We are really looking forward to this vacation. I see there is a storm approaching the end of this week. Do you think we'll be good for next week? — Robin H

Answer: The storms that we've been watching of late are Tropical Storm Bret and a potential tropical storm that may be named Cindy by the time you read this. So far, it appears neither will have a sizable effect on Cancun during the time frame you're asking about, as Bret is expected to both stay somewhat south and weaken as it continues westward, while Cindy will be well northwest of the area (and likely inland over the southern U.S.) by then. While we can't make guarantees something will not change that far in the future, so far it appears Cancun will have rather typical weather for the season, with a mix of sun and clouds and an occasional period of showers and thunderstorms. We hope you have a good visit!
Jun. 22, 2017 | Tags: hurricanes, preparedness

Question: Can an approximate dew point/humidity % be attached to daily or hourly 7-day forecast weather app? — Mark Hurley

Answer: We don't currently have a means of adding that directly to the apps, but may be able to in the future. However, if you visit our web site, either through a web enabled computer, the browser in your phone or tablet, or by choosing the "WRAL WeatherCenter" link within the "WRAL Weather Alert" app, you can get projected dew point values and relative humidity out through 7 days by clicking the "View Hourly Forecast" link above the 7-day section, and then looking just below the hour-by-hour forecast that appears, and clicking the "More Details" link.
Jun. 21, 2017 | Tags: humidity/dew point, wral.com

Question: Thanks guys!!! I wish I could send you the snips I have saved. One is a picture of the radar showing a string of storms approaching us....lots of red in it. The other is the hourly forecast showing all 0% from 8 pm on to 2 am. So now I'm wondering if I'm going to be safe riding my bike home from work tonight at 1130... — Tim

Answer: Your message refers to the evening of Tuesday, June 13th, when we expected a slight chance of showers or storms into the early evening from around the Triangle north and northwest, with rapidly decreasing rain chances after that. As it turned out, a band of intense storms over the Triad area did indeed rapidly dissipate as they moved in our direction, and only a few brief/light showers made it into parts of Person, Alamance and Chatham counties that evening, and those were likely gone by the time of your planned ride (your note didn't specify which part of our viewing area you were located in, so we aren't sure whether you would have been in a part of the area that had a non-zero precipitation probability into the evening). We do suggest checking both our written forecast descriptions (part of the 7-day forecast display) for both day and night periods in addition to checking hourly forecasts. giving somewhat more weight to the written descriptions.
Jun. 19, 2017 | Tags: past weather, wral.com

Question: Does your website indicate the details of current pollen and/or environmental allergen counts? Those of us with bad allergies would really benefit from knowing this before walking out the door each day, to know what preventative measures (i.e., medication or inhaler) to take to minimize symptoms. — Carole

Answer: We do have links to that information on our site. Just click on the "resources" link near the top of the main weather page, and scroll down to select the second page of the resources list. There you'll find links labeled "Daily Pollen Count Forecasts," which takes you to a map where you can click your way to a 5-day forecast of allergen levels and types for a number of cities across NC, and "NC Division of Air Quality Pollen Count," where you can see a graph of recent pollen counts taken in Raleigh. Near the top of that graph is also a link to see the latest available tabular report, which includes a listing of what the top observed pollen species are, and also includes a link to a calendar where you can retrieve previous written reports for any date during the season.
Jun. 18, 2017 | Tags: pollen, wral.com

Question: My temp receiver is on the N side of the house. We have nothing to protect it from the evening sun until it goes behind the tree line. Is there something I can do assure a correct temp in the evening hours before the sun goes down? — John Shepherd, Jr

Answer: The main concern here is to site the temperature sensor so that it is well ventilated, is not close to a strongly heated wall, HVAC unit or paved area, and is protected from direct sunlight, which sounds like the primary issue you have. You could house it in a ventilated shelter unit that you could either make (search the web for "Stevenson Screen," or see the article at www.weather.gov/rah/edu2), or there are smaller plastic shields that you can purchase for around 15-20 dollars. You would want to search for a "radiation shield" which can be found at a number of weather instrument specialty stores, some home supply stores, and a few other sources. They are small, white, louvered enclosures that keep direct sunlight off the thermometer but still allow air to flow through freely.
Jun. 17, 2017 | Tags: instruments

Question: Why is the moon red tonight? — Clinton Lilly

Answer: You didn't mention the time at which you observed the red-appearing moon, but we would guess that it was very close to moonrise, when the low altitude of the moon above the horizon leads to its light passing through a long fetch of the atmosphere on its way to your eyes. Air scatters a lot of the shorter wavelengths (blues and greens) out of the light passing through it from the moon (or other distant light sources), so that what remained was made up of the longer (yellow, orange and red) wavelengths that are not scattered as strongly. While this effect is noticed even on typical clear nights when the moon is very low, it can occur when the moon is higher if the right size range of additional particles are in the air due to smoke or pollution, and when the moon is quite low these can lead to even more reddening than usual.
Jun. 15, 2017 | Tags: astronomy, atmospheric optics

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