Is it a HEAT WAVE?

Posted by NBC12 Meteorologist Andrew Freiden

Some weather terms can’t be defined by numbers alone.  A “Heat Wave” is one of those terms.  It’s defined by qualitative rather than quantitative terms.  One person’s heat wave can be another’s hot spell.  In my opinion the numbers we are about to get over the next 5 days (or more) would qualify as a heat wave based on the following definition from the American Meteorological Society’s “GLOSSARY OF METEOROLOGY”

heat wave—(Also called hot wave, warm wave.) A period of abnormally and uncomfortably hot and usually humid weather.

To be a heat wave such a period should last at least one day, but conventionally it lasts from several days to several weeks. In 1900, A. T. Burrows more rigidly defined a “hot wave” as a spell of three or more days on each of which the maximum shade temperature reaches or exceeds 90°F. More realistically, the comfort criteria for any one region are dependent upon the normal conditions of that region. In the eastern United States, heat waves generally build up with southerly winds on the western flank of an anticyclone centered over the southeastern states, the air being warmed by passage over a land surface heated by the sun. See also hot wind.
          Ward, R. de C., 1925: The Climates of the United States, 383–395.


Whatever you call it– It’s going to be hot.  Do your best to stay cool!


8 Responses to Is it a HEAT WAVE?

  1. luke s. says:

    thanks for taking the time for clearing that up, i wonder if most people understand how the temp is taken? this past sat. my thermometer (which gets direct sunlight at about 3 pm) was reading about 115 F but the one in the shade was 98 F

  2. afreiden says:

    Luke: It’s actually a little of both! Official NWS readings are taken in a vented box that’s in an open area. The temperature is taken in the sun to get the ambient temperature but the thermometer doesn’t warm up due to direct sunlight (or get cooled off due to rain falling on it).
    Let’s see if this I can get this link to work… for a picture of one of the vented shelters:

    -Andrew Freiden

  3. luke s. says:

    not really a comment but a question, i have a friendly bet with a buddy . i say the high temp recorded for the day at the airport is recorded in the shade. he says in the sun. how is the official temp recorded? (shade, sun, on the ground, in the air etc.) btw thanks for the cool front, i work in a non a/c auto shop. its been tight in here for for the last week. but i guess it could always be worse.

  4. Karen H says:

    Ask any of the athletes who were in the fast-pitch softball tournament in Hopewell VA yesterday and today if its a heat wave and they will tell you! These girls played when it was a 105+ on the fields. They drank their fluids, used wet bandana’s and I didn’t see one succumb to this heat. So handling it the right shows that you can function (and excel) and we simply have to get used to it. This is Richmond VA folks and I don’t think its going to change alot.

  5. […] case you don’t live in the southeast, and in the event that you care, we are having a heat wave. Of grand […]

  6. Jim Duncan says:

    Here’s a link to a NOAA press release issued today re our cool spring:

  7. bobby_r says:

    Richmond, Hot Weather Data Facts
    The biggest reason many question global warming is because of there are many data facts that tell us otherwise. Lets start with the information given by DD about Richmond’s present heat wave. The actual weather data statistics point to a major fact blunder given by DD about Richmond’s record highs being in the mid 90’s for this time of the year… That statement is only partially true. The NWS data statistics give the following facts. During the month of June only one record high is in the mid 90’s. That record high is 96 degrees on June 6, 1937. All other record highs for Richmond during the month of June range from 97 degrees to 103 degrees. There are only 3 days in June that the record high temperature is 97 degrees. There are 13 days in June that the record high is 100 degrees or higher. Thats nearly one half the month. By the way, Richmond’s first 100 degree record day was on May 28, 1941. Another shocker is that Richmond has 8 days in March that the record high reached 90 degrees or higher. Richmond’s first 90 degree high was 91 degrees on March 17, 1945. In March 1907 Richmond had 5 days of record high temperatures, 94,87,87,91 and 94. July only has 3 days that record high temperatures has not reached 100 degrees, one is 98 degrees and the other two are 99 degrees. Richmond’s last record high 100 degree day is Sept. 11, 1983. October has 14 days that the record high is 90 degrees or higher, with the last 90 degree day being October 16, 1897. With regards to 80 degree temperatures in Feb. Once again the real data statistics prove that it is not unusal what so ever for Richmond to reach 80 or higher in Dec. Jan. or Feb. The data statistics, again prove this fact. Since weather data has been recorded in Richmond, Va., beginning in 1897, Richmond reaches 80 degrees or higher in 10% of its winters. A whopping 85% of Richmond winters reach 70 degrees or higher. Richmond has never had a winter that the temperature did not reach at least 60 degrees. Richmond averages 41 days per year of 90 degrees or higher, with a record number of 90 degree days being 70 days in 1976 or 1977. It’s interesting to note that many of the actual data facts were set many, many, many years ago long before some in our world began trying to control our lives and destiny. I’m not a meteorologist but I do and have studied real statistical data not some man made model or some short term data that has yet been proven. While Richmond has it whopping heat statistics there is always the other end of the spectrum that is recorded in other places in the country because they experience long periods deep cold weather. The information given here is a small taste of weather statistical data that the global warming people fail to tell us nor do they want us to know the actual data recorded. We only receive half truths from them and some of the data reported by them has been proven to be flat out lies. They claim to be so open minded, however, I haven’t found that to be true. They don’t like hearing the other side of the argument. They like changing the actual facts to suite themselves and their agenda.

  8. DD says:

    I’m really wondering how anyone can question global warming at this point. And the scary thing is, it’s happening almost immediately instead of 20-50 years off. This is not a heat wave, it is the destruction that we’ve done and continue to do to our planet. I don’t understand how meteorologists can downplay this. We are 20 degrees above average, the record high is in the mid 90s, which is actually going to be our coolest reading for the next week. But hey, what can we expect when it was 80 in February.

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