SKYWARN

Special WX Bulletin

from WB5OCD / W5ED

April 1999

Sunshine

SPOTTER TIPS
SAFETY FACTS

  Welcome | Net Operations | Spotter Tips & Safety Facts | Lightning Safety

Much was accomplished during the month of March. Training sessions were conducted on net operations and how to be an effective net control station (NCS). Jim Butch from the NWS in Jackson, Billy Bob Sekul from the Jackson ARC SKYWARN Center, and Malcolm, W5XX, the ARRL Section Manager for Mississippi was here on the 25th for the Storm Spotter class. The turnout was very good for all of these programs and over half the storm spotter class were HAMs or their guests.

The emergency net was also activated twice during the month for severe thunderstorms moving through our area. The nets went very well. I received comments from several sources outside the amateur community about how professional you sounded. Thanks.

SPOTTER TIPS - What to report:

• tornadoes • funnel clouds • coastal flooding • unusually high surf • rotating wall clouds • damaging thunderstorm winds • persistent heavy rains/floods • large hail • snow depth/ice accumulation • any weather phenomena causing death or serious injury • your call or other ID • where & when the event occurred (reference landmark or city) • damage or injuries

MPH INDICATIONS

25-30 large branches moving; whistling heard in wires.

30-40 whole trees moving; inconvenience in walking against wind.

40-45 breaks twigs and small branches, impedes walking.

45-55 larger branches and weak limbs may break; slight structural damage occurs.

55-65 moderate structural and tree damage.

> 65 heavy to severe structural and tree damage.

Bullet Tornadoes and rain shafts can look alike. Look for rotation and upward motion. Also, look for other visual clues, such as the wall cloud, overshooting tops, storm rotation, etc. If you aren't certain of what you see, contact your NCS and your object will be viewed from a different direction if possible to get a better idea what you have.

Bullet Be cautious and don't report a tornado if what you see is actually a funnel cloud.

Bullet Don't forget your battery operated NOAA radio. It could save your life.

SAFETY FACTS:

Tornadoes in our area usually move in a southwest to northeast direction. If it appears to be standing still it may be moving directly toward you.

The largest hail generally falls just preceding the tornado. Report the size of the largest hailstones. Use a ruler or the following as a reference. 1/4" is pea size, 1/2" inch is marble (from NOAA guide), 3/4" is dime, 1" is quarter, 1-3/4" is golf ball, 2-3/4" is baseball.

When reporting wind speeds or gusts, tell whether they are measured or estimated. the modified Beaufort Scale below will help you estimate speeds.

OTHER NOTES:

Bullet Congratulations to all those that have upgraded or received their HAM license in the past couple of months.

Bullet If you have info on how to make wind speed and direction indicator and the parts lists required to do so and would like to teach the rest of us how to put a WX station together please let me know.

Bullet Hope you have a good safe month.

Jim WB5OCD

Welcome | [Net Operations | Lightning Safety | Last Modified: 03/10/2002