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Recent Questions

Question: WRAL continually has higher daily forecasted temps. For instance, this week (Mon-Fri), you're approximately 3 degrees per day warmer than other sources. What causes this? Is your location a factor? I can't figure out why? — Dan

Answer: We suspect that if you kept track over a long period of time, there might not be so consistent a difference toward warmer or colder by a few degrees, but it has been the case that in the past few weeks we've had several scenarios in which we both felt the pattern that was developing was one that would lean toward higher than normal temperatures, and we had also noted that calculated temperature projections from a number of computer models (both in the way of "raw" output, and statistically adjusted forecasts that are intended to reduce biases) were frequently under-predicting highs by anywhere from around 2-5 degrees under some conditions. When we felt this was an applicable issue, we forecast temperatures that we felt were most likely to occur, and as you noted in a number of instances our numbers were on the high side of those you'd see elsewhere. Fortunately, at least during those few weeks, the higher numbers often proved to be verified by later observations.
Sep. 28, 2016 | Tags: heat, past weather

Question: Back in the late eighties/early 90's, in January, in Durham (presumably in the surrounding areas as well), we had a very hot day, at least in the 80's followed by a day where it snowed significantly (6 to 8 inches) that was not forecast to occur. What reference(s) would you recommend that I use to find data on this event? — Ruth

Answer: You could try to narrow down the possible winter storm events by using the Winter Storms Database feature of the State Climate Office web site, at climate.ncsu.edu/climate/winter_wx/database.php. After finding the event that you think most resembles the timing and character of the storm you recall, you can use the Almanac section of our web site, and it's "Get Historical Data" feature, to look up temperatures observed at the RDU airport or other nearby locations in the days leading up to the snow.
Sep. 27, 2016 | Tags: cool sites, past weather, snow

Question: Would you please recommend a good website where I could find local (Chapel Hill) weather information such as the high and low temperatures for a given day, number of days the high temperature reached 90 degrees, number of days the low temperature was below freezing, amount of rain on a given day, amount of rain for the year, etc.? — Richard Woeller

Answer: You can look a lot of that up using the "Almanac" section of our web site, which will link you to historical weather information for a selected date - it will default to RDU, but you can change locations from the resulting page, as well as change dates or choose to view data over daily, weekly or monthly time frames.

While there's a little bit of a learning curve, you can also run more sophisticated searches to find averages, or the number of times that thresholds were exceeded for defined periods of time, and many other statistics, using the database tools at xmacis.rcc-acis.org/. If you're really into delving deeply into this tool, there is a one hour user training video link at the bottom of the home page for the tool. There is also a short written tutorial we found online for a few key types of searches that might help you get familiar with the interface more quickly. It's located at www.srh.noaa.gov/images/ffc/climate/xmACIS2_guidance.pdf.
Sep. 26, 2016 | Tags: cool sites, past weather

Question: What is an areal flood? — Arr Schaller

Answer: It's probably easiest to describe by comparing it to the other common flood warnings that the National Weather Service may issue, since they differ largely in the sense of how quickly the onset of flooding may occur, and how localized flooding is expected to be. They define flash flood warnings and areal flood warnings in the following ways:

A Flash Flood Warning is issued for flooding that normally occurs within six hours of heavy or intense rainfall. This results in small creeks and streams quickly rising out of their banks. Dangerous flooding in areas near these creeks and streams, as well as low-lying flood prone areas, develops very quickly and is a significant threat to life and/or property.

An Areal Flood Warning is normally issued for flooding that develops more gradually, usually from prolonged and persistent moderate to heavy rainfall. This results in a gradual ponding or buildup of water in low-lying, flood prone areas, as well as small creeks and streams. The flooding normally occurs more than six hours after the rainfall begins, and may cover a large area. However, even though this type of flooding develops more slowly than flash flooding, it can still be a threat to life and property.

A third type to be aware of is the River Flood Warning, which is issued when runoff from extended periods or large areas of heavy precipitation cause rivers to reach or exceed established elevation levels that correspond to minor, moderate or major flooding levels at designated gauge locations along the river. While the other warnings typically remain in place for a few to several hours, river warnings can sometimes stay in effect for days.
Sep. 25, 2016 | Tags: flooding, preparedness, rain

Question: When are the earliest and latest dates Raleigh has seen 90 degrees? — Caravaggio

Answer: In records stretching back to 1887, the earliest occurrence of 90 or higher for Raleigh was on March 12, 1990, while the latest was on October 10, 1939. The average date of the first 90 or higher of the year is May 10th, while the average date of the last 90 or higher is September 11th.
Sep. 24, 2016 | Tags: heat, normals, records/extremes

Question: Can you tell me if there is a way to look up wind directions from past days? The specific day I was looking for was September 10th 2016. — Jonathan

Answer: To track wind direction over time, and see that data graphically, you can click the "Almanac" link on our web site, then enter your date under "Get Historical Data." The resulting page will default to data from the RDU airport, but does include a "Search for Another Location" box. Also, once you are on that page, you can change the view between daily, weekly and monthly, for example, and scroll down a bit to see graphs over that time span of several variables, wind speed and direction included. There are also links near the top of the page to step to the previous or next day, week or month, and you can see a table of text observations that include winds as well, by scrolling down past the graphical data.
Sep. 23, 2016 | Tags: past weather, winds, wral.com

Question: When do you think we will start seeing fall weather? (75 degrees or lower) — Heather West

Answer: We'll likely have a day or two here and there last weeks of September that stay in the upper 70s, but consistently seeing highs in the lower 70s or below could easily take until two or three weeks into October. We don't have any confident way to predict specific stretches of day-to-day weather that far in advance, but by that time frame we have reached a point where our normal high temperatures have declined into the low to mid 70s range.
Sep. 22, 2016 | Tags: normals

Question: Could we have a tornado in the fall season? — Amy

Answer: It can't be ruled out, as tornadoes are possible in any month of the year in our part of the state. Climatologically, they are most numerous in the Spring, during the period from March to May, with a small secondary peak in frequency in the September to November time frame. Fatalities from tornadoes are rather rare in our state overall, but it is notable that November has seen the third most tornado deaths, with 19 during the span from 1950 to 2014, behind the months of March (48) and April (38), as documented in a recent undergraduate student project carried out under the guidance of the Raleigh NWS office.
Sep. 21, 2016 | Tags: preparedness, tornadoes

Question: Why do the prevailing winds change in September and October? — Brian

Answer: In September and October, as we transition out of summer and into the Fall, the jest stream begins to move on average to a more southerly position and as a result we begin to have more frequent passages of the polar front south of our position. However, during this early part of the transition to a colder regime, it is common from fronts to move a short distance south of us and either stall or wash out, while a ridge of surface high pressure centered near New England or off the northeastern coast of the U.S. either stalls for a few days or moves slowly, with the high pressure ridge extending for several days down the eastern seaboard, focused on the east side of the Appalachian mountains. This high pressure position results in winds anywhere from northerly to easterly for several days at a time on a number of occasions during those months, leading to the prevailing direction being northeasterly. That said, as with the remainder of the year, it is possible to have winds from any direction during September and October, but they are somewhere between north and east often enough to average out to northeasterly. For the rest of the year, winds can also be variable, but they are frequently enough between south and west for that to be the predominant direction for all other months. During the summer, for example, winds are often fairly light but strongly favor a southwesterly direction due to the near-stagnant position of the Bermuda High. During the core of winter there is a noticeable tendency for winds to shift to northwesterly behind cold fronts, northeasterly for a short time with high pressure areas northwest of us, and southwesterly as high pressure centers move to our east or southeast and new cold fronts approach from the west or northwest.
Sep. 20, 2016 | Tags: fronts & airmasses, general meteorology, winds

Question: How many 90+ degree days did Raleigh have in 2015? — Linda

Answer: The Raleigh-Durham airport reported high temperatures of 90 or higher 52 times in 2015. For perspective, the long-term average for the Raleigh area in records since 1887 is 43 days, while the current "normal" (defined as the 30-year average from 1981-2010) is 48. The year 2010 had the most so far with 91 days, while the lowest number on record was 11 days in 1889.
Sep. 19, 2016 | Tags: heat, past weather, records/extremes

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