System and method for projecting storms using NEXRAD attributes

The subject invention provides an improved system and method for combining data obtained from the NEXRAD.TM. system of the National Weather Service ("NWS") with geographical and topological data base information to achieve an improved and informative graphical storm-tracking display able to project the movement of a storm with a single user-operation. The method of projecting storm movement includes the following steps: collecting NEXRAD data attributes from a weather data source; calculating storm position using the collected NEXRAD attributes; calculating projected storm movement using the storm position and the collected NEXRAD attributes; displaying a graphic representation of the projected storm movement.

II. FIELD OF THE INVENTION 
The present invention relates to an improved system and method for 
combining data obtained from the NEXRAD.TM. system of the National Weather 
Service ("NWS") with geographical and topological data base information to 
achieve an improved and informative graphical storm-tracking display able 
to predict and project the direction of a storm with a single 
user-operation. 
III. BACKGROUND OF THE INVENTION 
NEXRAD is a system of weather services provided by the NWS. NEXRAD employs 
a system of radars scattered throughout the country which provides weather 
data to subscribers. Subscribers, such as television stations desiring to 
transmit weather broadcasts, use data from the NEXRAD system in its basic 
form. Current systems of subscribers typically extract simple storm 
information from the NEXRAD data to provide viewers with basic storm 
location information. 
One NEXRAD service is the "NEXRAD Attributes." This service provides the 
subscribers with detailed information concerning storms detected at each 
NEXRAD radar site. The NEXRAD Attributes data includes the following 
information for each storm: 
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ID a unique 3-digit identifier 
AZ the direction of the storin in degrees from the 
radar source 
RANGE the distance of the storm in nautical miles from 
the radar source 
TVS the likelihood of a tornado vortex signature (Yes 
or No) 
MESO the likelihood of mesocyclonic activity (Yes or 
No) 
HAIL the likelihood of hail (% change of hail, % chance 
of severe hail, approximate hail size in inches) 
DBZM the maximum DBZ level (a measurement of 
precipitation intensity) 
FCST.sub.-- ANGLE 
forecasted movement angle (storm path) in degrees 
FCST.sub.-- MVMT 
forecasted movement speed in nautical miles per 
hour 
______________________________________ 
The typical current NEXRAD system used by a NEXRAD subscriber receives 
NEXRAD data via a satellite downlink or over a wired network connection 
into a computer, such as the computer illustrated in the attached FIG. 1. 
Then, the current subscriber's system extracts the azimuth and range 
information of the subject storm. From this information, the current 
systems can plot a two dimensional representation of the storm. Most of 
the other information in the NEXRAD Attributes goes unused by current 
systems, although the user, typically a meteorologist, can review this 
data manually. 
One problem with a subscriber's current system is that in order to predict 
the movement of a storm, the user must manually create projections from 
the NEXRAD Attributes data. Current systems do not have the capability to 
create a graphical representation of the storm movement from the NEXRAD 
Attributes data without substantial human involvement. 
Moreover, the current graphical storm display is typically limited to 
simple two dimensional representations of the storm's location and little 
else. Typically the viewers of weather displays based on the current 
systems have only a vague concept of the proximity of the storm to their 
location. Current systems are incapable of displaying NEXRAD projection 
information concerning those storms in any appreciable graphical way. 
IV. SUMMARY OF THE INVENTION 
A method for projecting storms using NEXRAD attributes comprising the steps 
of: (a) collecting NEXRAD data attributes from a weather data source; (b) 
calculating storm position using the collected NEXRAD attributes; (c) 
calculating projected storm movement using the storm position and the 
collected NEXRAD data attributes; (d) displaying a graphic representation 
of the projected storm movement; (e) determining the communities in the 
path of the projected storm movement. 
In addition, the present invention, in a preferred embodiment further 
comprises the following steps: (f) displaying the communities indicating 
the estimated time of arrival for the projected storm; (g) sorting 
multiple storms; (h) displaying the sorted storms in order of priority; 
and (i) displaying single storm details.

VI. DETAILED DESCRIPTION OF THE INVENTION 
The present invention improves over the prior art by utilizing the NEXRAD 
Attributes storm projection information, represented by the variables 
FCST.sub.-- ANGLE and FCST.sub.-- MVMT above and shown in FIG. 3, to 
provide the users of the present invention the ability to graphically 
display storm projection information with a single operation. The present 
invention extracts the NEXRAD Attributes storm projection information and 
adapts that information for graphical display. The use of the projection 
data in the present invention allows the user to have the storm location 
information graphically displayed, such as on a computer monitor screen or 
television set, overlaid with a graphical representation of the projected 
movement of the storm. 
The steps which the present invention utilizes to achieve a storm 
projection system that will provide the user with storm prediction 
information in one operation can be briefly summarized as follows: 
The first step is collecting NEXRAD Attributes for use by the storm 
projection system by receiving NEXRAD Attributes information via a 
satellite downlink, wired network, or other information transfer medium, 
and storing this information in a database. 
In a preferred embodiment, the database contains the following attributes 
for each storm: 
______________________________________ 
Attribute Range of Values 
______________________________________ 
The presence of a Tornadic Vortex Signature (TVS). 
YES or NO 
The presence of Mesocyclonic activity (MESO) 
YES or NO 
Chance of Hail 
0% to 100% 
Chance of Severe Hail 0% to 
100% 
Hail Size in inches 0.00" 
to 4.00+" 
Maximum Storm DBZ (measurement of rainfall 
30 to 75+ DBZ 
intensity) 
Height of max DBZ reading in the Storm 
1-75 thousand 
of feet 
Storm Height 1-75 
thousand 
of feet 
Storm position (latitude and longitude) 
N/A 
Storm forecasted angle 0 to 359 
degrees 
Storm forecasted movement 
0 to 60+ mph 
Storm Vertically Integrated Liquid (VIL) 
0 to 75+ kg/m.sup.3 
______________________________________ 
The database information is accessed to report the contents and 
characteristics of storms and to track the storms in near real-time. 
Second, in response to a user request for a projection of a storm's 
movement, the system retrieves the NEXRAD Attributes information for a 
subject storm stored in the first step above. The user request may be made 
using a manual input device such as a mouse or keyboard as shown in FIG. 
1. 
Third, the system calculates a storm projection arc to create a graphical 
representation of the storm for display, said calculation comprising the 
steps of: 
(a) Using the storms offset in meters from the view center of the graphical 
display (FIG. 2) to find the storm's position in latitude/longitude; 
(b) Using the storm information (including fanout in degrees, direction in 
degrees, projection length in meters, and position as an offset in meters) 
to find the four corners of an arc describing the storm's projected path 
(the "storm projection arc"); 
(c) Using the storm information (including fanout in degrees, direction in 
degrees, projection length in meters, and position as an offset in meters) 
to find the storm's projected position after moving "length" meters; 
(d) Using the storm information (including fanout in degrees, direction in 
degrees, projection length in meters, and position as an offset in meters) 
to find the center of a bounding circle that helps define the limits of 
the projection; 
(e) Using the four corners of the storm projection arc to define the 
maximum latitude, maximum longitude, minimum latitude, and minimum 
longitude at which a place in this track may be positioned; 
(f) Using the four corners of the storm projection arc (see b above) to 
define the bounding lines of the arc that will define the storm 
projection; 
Fourth, a general database of geographical information (FIG. 3) is stored 
on the computer in the form of a database containing latitude and 
longitude information, as well as other identifying and prioritizing 
information for all known cities and communities, hereinafter "places", in 
the area of interest for a user of the present invention. 
In a preferred embodiment, the places may be further grouped and related 
based upon their geographic proximity to each other such as being members 
of the same county, same state, same region, etc. The selected groups may 
be identified by minimum and maximum longitude and minimum and maximum 
latitude. 
When determining which places are in the path of a storm, the following 
steps are performed: 
1. If the places are grouped as described in the preferred embodiment, and 
the group's minimum latitude, minimum longitude, maximum latitude and 
maximum longitude indicate that none of the places in the group are within 
the arc of the storm projection, then skip that group of places; 
2. Next, for each place not eliminated in step (1) above, do the following: 
(a) If the place's latitude exceeds the minimum or maximum latitude 
requirements--skip it; 
(b) If the place's longitude exceeds the minimum or maximum longitude 
requirements--skip it; 
(c) If the place's priority level indicates that it should not appear at 
this track range (based on user-defined parameter for this particular 
track)--skip it; and 
(d) If the place's latitude/longitude is not within the bounding circle 
(see above)--skip it. 
(The above elimination steps represent the preferred embodiment, but they 
may be performed in any order. In addition, the user may identify other 
bases for eliminating certain places from the eventual display. 
Fifth, if a particular place has not been eliminated, it is within the path 
of the storm. 
Sixth, by linear extrapolation, the current time, the storm's position, the 
storm's speed/direction, and the position of this place are used to 
determine the storm's ETA for this place. 
Seventh, the system displays the storm projection arc, a topographical map 
of the affected area, and iconic representations of the places affected 
(refer to FIGS. 3 and 4 for general diagrams of this step) overlaid on top 
of a graphical representation of the storm. 
FIG. 5 illustrates a preferred embodiment of a display of projected storm 
movements, the communities within the path of a storm, and the ETA for 
each community. 
Finally, in the case of multiple storms, a sorting technique is used to 
prioritize storms. The priorities for sorting are based upon the following 
criteria: 
1. The presence of a Tornadic Vortex Signature (a.k.a. TVS). This is either 
YES or NO. 
2. The presence of mesocyclonic activity (a.k.a. MESO). This is either YES 
or NO. 
3. The presence and estimated size of hail (size is measured in inches and 
is accurate to 1/4 of an inch). 
4. The highest recorded DBZ (a measurement of the intensity of the 
rainfall). 
5. The estimated storm speed in mph. 
These sorting criteria are in order of importance. The criteria are plugged 
into the following formula to determine the "weight" of the storm. The 
storm with the greatest weight has the highest priority. 
weight=0; 
if TVS presence 
weight=weight+1,000,000,000 
if MESO presence 
weight=weight+100,000,000 
if hail size&gt;0.00 
weight=weight+hail size * 10,000,000.0 
weight=weight+DBZ * 100 
weight=weight+speed (in mph) 
This formula tracks and assures that each criteria has a larger weight 
factor than its successor. 
It should be noted that, in addition to the storm prediction achieved 
through the novel and non-obvious use of the NEXRAD Attributes, the 
present invention improves over the prior art by merging the weather, 
storm, and prediction information described above with geographic and 
topological information to achieve an enhanced and visually-appealing 
display. This application allows the user to provide a graphical weather 
display which overlays storm information on top of actual geographical 
information. Combining these two forms of information allows the user of 
the present invention to provide to its viewers or consumers weather 
forecasting at its most advanced level. 
The ease with which the user can use the present system to obtain a storm 
tracking prediction, is evidenced by the fact that the user need only 
select the storm cell of interest, and the storm position is displayed 
automatically. Therefore, viewers of weather forecasting displayed through 
the use of the present invention will have available prediction 
information specifically tailored to the viewers' own viewing area. For 
instance, viewers in small towns that previously could only guess at what 
time a storm would arrive at their location may now be given that 
information in a highly accurate and graphically appealing way. This 
improvement will detail exact and highly precise times at which storms or 
other weather phenomenon will arrive at any of several towns or cities in 
a geographical database provided with the present invention. 
It should be understood to those skilled in the art that other 
modifications and changes can be made without departing from the spirit 
and scope of the invention and without diminishing its attendant 
advantages. It is therefore intended that such changes and modifications 
be covered by the following claims.