For years, the observations of storm chasers have provided valuable knowledge for research on the structure and evolution of severe storms in the plains. Local NWS offices and SELS forecasters have also benefitted from that. Some chasers also have contributed to NWS warning and verification by timely reports from the field; but that can be inconvenient or impossible at times. This issue has been beaten to death in Stormtrack so no need to light that controversy on fire again. As a SELS forecaster and a veteran of over 100 chases, I appreciate both perspectives. However, there is something we can do to bridge the gap between storm chasing and operational meteorology, to the benefit of both.
How many times have you opened an issue of Storm data only to find that your great storm last spring is incompletely listed or not there at all? This has happened to me and many others. Local NWS offices provide the statistics and summaries to Storm Data based on reports they receive, sometimes verified and revised with damage surveys. The SELS database and daily log of severe weather reports is, in turn, based on LSR's (local storm reports) sent out by NWS offices. If you see a 4-inch hailstone, or film a tornado, you shouldn't expect it in Storm Data unless you report it. Don't assume that, with all the other chasers and spotters out there, it will be recorded anyway. All the others may be assuming the same thing--if there are others watching the exact same event. It's best if you can get in touch with the NWS office responsible for the county where your event occurred, either later that night or within a couple of days after the chase.
Problem is, many chasers either do not know addresses and/or phone numbers for NWS offices or which office has jurisdiction over the place they saw the event. At SELS, we do. On the next page, there is a simple form you can use to record and report severe weather. make as many copies as possible, and pass them along to other chasers you know or meet in the field. A thunderstorm is verified as severe only if it produces 3/4 inch (dime size) or greater hail, 50 knot (58 MPH) wind gusts, wind damage, or a tornado. If you witness any of these, and cannot report them that evening or the next day to the proper NWS office, please fill the form(s) out and send them directly to me at the address listed on the form. I'll then forward all severe reports to the right NWS offices, so they can use them for case studies, Storm Data, and warning verification.
When chasing, take along a tape recorder and/or written log, so you will know exactly when and where something happened. Shoot plenty of pictures to look back over later. Noting the exact time (to the minute if possible) and location (1 mile north of Erick, OK or I-40 at the Erick exit) are most important. Most experienced chasers are talented at estimating gusts, so give your best estimate if you have no anemometer. Include a tape measure or ruler in your gear, for hail measurement. If the hail was already on the ground, about how long ago did it fall? Note any wind damage, even if it's just an uprooted tree or downed telephone pole. If you see a tornado, record both your location, and the distance/direction of the tornado from you.
Here are some things you can keep an eye on for the "other comments" section: if it was a tornado, how long did it last? What did it look like? Did it hit something; if so, what? If there is wind damage, do you know what caused it (tornado or downburst)? Describe in as much detail as possible what the damage looked such as what direction the tree fell or what parts of the house were left standing. In these days of federal budget problems, the NWS cannot survey all wind and tornado damage, so any detailed descriptions are greatly appreciated. Feel free to send copies of photos and video if you wish. Sometimes, that's our only way to verify the extent and nature of an event (for example, whether damage was tornadic, and what F-scale it fits).
NEXRAD is a great tool to help the forecaster warn, but it cannot verify a warning. Only people can (or an automated station, if it happens to be hit by a gust of 50 knots or more). An accurate climatology also improves watch and outlook verification, research case studies, and risk reduction efforts. Every report is greatly appreciated. We chasers can make a big difference!
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