Accurate and concise reports of damage are the most useful products that the ARPSC can
produce during and after a Skywarn activation. Our reports serve the Homeland Security
Department by providing situational awareness of the location and magnitude of storm damage
as it occurs. These reports are also used by the National Weather Service to issue Warnings for
items that were not visible to radar. After the fact, the NWS also reviews our reports and
compares actual damage to saved radar images from the time of the event. This enables
forecasters to better understand the relationship between radar images and actual weather on
Damage reports should be submitted as close to the time of the damage as possible. The
following outlines reporting process preferred by the ARPSC, Homeland Security and the
National Weather Service.
The reporting process is best described by the acronym T - E - L, short for Time Event Location.
Please provide the actual time of the event you are reporting. Real time reports assist the NWS
in issuing updated weather statements, Warnings and updates to existing Warnings. Your report
should include denoting the time as Actual.
If you come across damage after the fact, reports are still helpful. You should attempt to
determine the actual time by speaking with people in the area. If you can obtain the time of
occurrence, your report should denote the time as Actual. If the time cannot be accurately
determined, provide the most likely time and denote it as Estimated in your report.
If the time cannot be determined, simply denote the time as Time Unknown.
The Event portion of your report identifies the nature of the report. Items typically reported
include one or more of the following:
- High Winds
- Wall Clouds
- Tree Damage
- Clouds With Rotation
- Power Lines Down
- Funnel Clouds
- Damage To Structures
High Winds are winds in excess of 40 mph. The chart on the Skywarn home page can be useful
in estimating wind speed. If you have an anemometer please use that to determine wind speed.
When you provide a wind report please indicate whether it is Estimated or Measured.
Hail of Ό inch diameter or larger can be reported. Please use the chart on the Skywarn home
page to determine hail size.
Flooding should be reported when water reaches a level that covers a roadway from curb to
Clouds With Rotation is an observation possible only in daylight hours. The rotation is clearly
defined around the center of a rotating circle.
Funnel Clouds are rotating cone shaped formations descending from clouds. Many times these
are incorrectly reported as tornadoes. While similar in structure, a funnel cloud only becomes a
tornado when the funnel reaches and makes contact with the ground. When reporting a funnel
cloud you should also include its direction of travel.
Wall Clouds frequently precede tornadoes. Please visit the National Weather Service website
for a detailed description and photographs of wall clouds.
Tornadoes are rotating cone shaped formations descending from a cloud and making contacting
with the ground. Depending on the strength of the tornado, a debris cloud may be visible.
When reporting a tornado please indicate it direction of travel.
Tree Damage includes any damage caused by wind. Reports should begin with numerous twigs
and small branches (up to 1 inch diameter) being broken and falling to the ground. The next
level includes tree limbs being broken from trees. The diameter of the broken branch should be
estimated and included in your report. With stronger winds the trunk of a tree may be
completely broken off. In your report please indicate that the trunk was snapped and provided
the estimated diameter of the trunk where it was broken. The final form of tree damage is the
complete uprooting of the tree. This is evidenced by the trees root ball being pulled from the
ground and completely visible. When reporting please submit this damage as an "Uprooted
Tree" along with an estimate of the trunk diameter near the base of the tree.
Power Lines/Utility Poles Down all power line down incidents should be reported to net
control. Additionally, any utility pole damaged during a storm should also be reported to net
Damage To Structures should be reported for any incident where shingles have blown from the
roof to major structural damage. Samples would include; shingles blown off roof, garage roof
blown off with damage to walls, etc.
The final component to the report is the location of the event. An accurate location provides the
information necessary for the NWS to enhance its forecast capability and provide additional
weather statements in the case of an imminent threat to a specific well defined area. As a
service to Homeland Security an accurate location provides the building blocks to develop a
picture of the area affected, the magnitude of the event and, when coupled with GIS data, the
population within the damage area. When a potential threat is moving, the direction of its
movement becomes an additional component to the report.
The location of an event should describe the location as close as possible. This would include an
address (which is not always practical), the closest major cross roads and the direction from that
point and the city or township where it is located.
- "At 1540 hours - clouds with rotation just north of 14 Mile and Orchard Lake Rd in West
Bloomfield moving east northeast"
- "At 2015 hours - power lines down and arcing with the utility pole broken on the west side of
Coolidge just south of Long Rd in Troy."
- "Time unknown 4 trees down, 2 uprooted, 2 snapped trunks trunk diameter of all 18 inches
on the west side of Milford Rd south of General Motors Rd in Milford."
- "At 1842 hours winds in excess of 40 mph, estimated on Rochester Rd north of Wattles in
- "At 1933 hours winds in excess of 55 mph estimated, multiple trees uprooted or trunks
snapped, estimated trunk diameter of 30 inches, garage roof blown off with damage to the
walls at 5729 Cherry Crest Dr, just southwest of Walnut Lk Rd and Orchard Lk Rd in West
- "At 1417 hours 3/4 inch size hail accumulating 4 inches in 10 minutes at Troy Fire Training
Center, east side of John R south of Long Lk Rd in Troy."
- "Right now...right in front of me...huge TWISTER!!! AAAAHHHHHHHHHHHHHHHHHHHHHHHHHHHHHH " (end of transmission)