Severe Weather Page








 

Welcome to my weather page.   I am a net control operator for the Rockford Metro Skywarn  group when the NWS issues a watch/warning for our area.  

Below I would like to go over a few things.


What should I report?
Report these observations to your local Skywarn net control. He/she will determine if it warrants passing the report on to the National Weather Service.

TORNADO
WATERSPOUT
FUNNEL CLOUD
Organized, persistent, sustained rotation

WALL CLOUD
Organized, persistent, sustained rotation

HAIL
Nickel size or larger. Report the largest size hailstone

WIND GUSTS
40 mph or higher. Specify estimate or measurement

FLOODING
Flooding that impacts roads, homes or businesses.

RAIN
1/4 inch or more within a 15 minute period.

STORM DAMAGE
Damage to structures (roof, siding, windows, etc)
Damage to vehicles (from hail or wind)
Trees uprooted or large limbs down
Power/telephone poles or lines down, or direct lighning strike injuries

HEAVY SNOW
1″ or more per hour, accumulations of 2″ or more

ICE JAMS
Ice jams on rivers or streams

Again, reports should provide as much detail as possible to describe the where, when, how, etc of the event.
Some commonly used hail sizes
Pea .25 inch Golf Ball 1.75 inch
Half-inch .50 inch Hen Egg 2.00 inch
Dime .75 inch Tennis Ball 2.50 inch
Nickel .88 inch Baseball 2.75 inch
Quarter 1.00 inch Tea Cup 3.00 inch
Half Dollar 1.25 inch Grapefruit 4.00 inch
Ping Pong Ball 1.50 inch Softball 4.50 inch
General Guidelines for Estimating Wind Speeds
30-44 mph (26-39 kt) Whole trees in motion. Inconvenient walking into the wind. Light-weight loose objects (e.g., lawn furniture) tossed or toppled.
45-57 mph (39-49 kt) Large trees bend; twigs, small limbs break and a few larger dead or weak branches may break. Old/weak structures (e.g., sheds, barns) may sustain minor damage (roof, doors). Buildings partially under construction may be damaged. A few loose shingles removed from houses.
58-74 mph (50-64 kt) Large limbs break; shallow rooted trees pushed over. Semi-trucks overturned. More significant damage to old/weak structures. Shingles, awnings removed from houses; damage to chimneys and antennas.
75-89 mph (65-77 kt) Widespread damage to trees with large limbs down or trees broken/uprooted. Mobile homes may be pushed off foundation or overturned. Roof may be partially peeled off industrial/commercial/ warehouse buildings. Some minor roof damage to homes. Weak structures (e.g., farm buildings, airplane hangars) may be severely damaged.
90+ mph (78+ kt) Many large trees broken and uprooted. Mobile homes damaged. Roofs partially peeled off homes and buildings. Moving automobiles pushed off the road. Barns, sheds demolished.
How Should I Report an Obervation?
(ranked by NWS preference)
FIRST CHOICE: On your local Skywarn Amateur Radio Reporting Repeater!
SECOND CHOICE: NWS #
THIRD CHOICE: eSpotter








ALL reports should include the following information:

WHO are you? Report your ham callsign or spotter ID (or phone number, or any other means of identification) so the NWS can contact you to verify the report. Without this information, the NWS cannot use your report.
WHAT did you see?
WHERE did you see it? Report the location/approximate location of the event. Be sure to distinguish clearly between where you are and where the event is thought to be happening (.I.m 5 miles north of Mayberry. The tornado looks to be about 5 miles to my northwest.).
WHEN did you see it? Be sure that reports that are relayed through multiple sources carry the time of the event, NOT the report time.
Any other details that are important – How long did it last? Direction of travel? Was there damage? etc.


Generally when a thunderstorm forms, you’ll see the heavy rainfall on one end, a dark, rain-free cloud base on the other, and in the center a lowering “wall cloud.” About 25 percent of the time, a wall cloud actually becomes a tornado.

Allsopp said the place to keep an eye on is that center, where the strong updraft is found. That’s where the warm, moist air rises into the storm. There are three key things to look for when determining whether a tornado is forming:

Rapid rotation (is the lower portion of the cloud moving in a circle?)
Strong inflow (is wind and debris being pulled toward the wall cloud?)
Clear slot (is there an opening that wraps around the backside of the storm?)
What’s Not a Tornado?
Spotting a tornado can be tricky because there are so many impersonators, Allsopp said. There are a lot of things that might look like tornadoes at first, but don’t call it in immediately if you aren’t sure.

“Just wait a minute and see what it does,” Allsopp said. “If it doesn’t spin, don’t call it in.”

For example, rain in the distance may sometimes appear shaft-like when falling from clouds. Smoke coming from the ground up toward the sky may look like a funnel. And there’s such a thing as “gustnadoes,” which is basically heavy wind kicking up dust, sometimes even into a slight rotation. Some dark clouds may have ragged edges and finger-like clouds hanging below. These are not tornadoes, and neither is something that doesn’t extend from the storm cloud down to the ground.

Safety Tips for Spotting
Allsopp didn’t encourage people to go out storm chasing in their cars, especially in Chicago traffic. Most people do it from their back yards or offices.
Right Hand Rule: If you do go chasing storms, stay to the southeast of it. The heavy rainfall should be to your right with the storm heading northeast. That way, you can see the entirety of the tornado without the rain blocking your line of sight and without you getting caught up in the middle of the tornado.
Don’t try to outrun a tornado in your car—they can move up to 60 mph of more.
Have an escape route.
Seek shelter in a sturdy building away from windows, or as a last resort lie down in a ditch or low spot.
Don’t spot at night, because visibility is so low.