Frequently Asked Questions
How do you compute speed, density, and risk scores ?
Each morning, we synthesize a few public Covid-19 datasets. This process gives us raw values for new infections, new deaths, active cases, and population sizes.
We then unbundle the equation for momentum, borrowed from physics. Density (how much virus is in your area) is our mass and speed (how fast the virus is growing in your area) is our velocity.
We calculate density using the # of active cases in your community, adjusted per capita.
We calculate speed as a ratio of the average # of new cases in the past week over the average # of new cases in the past two weeks. We chose this two week time frame for two reasons. First, there appears to be a weekly, cyclic pattern in the Covid-19 data consistent across the globe and we wanted to capture two full cycles. Second, the virus remains largely contagious within this same two week period.
Our final risk score is influenced by our density and speed calculations. We want this value to be both easy to understand and easy to translate into three levels of caution. The basic formula for risk is the following:
Red = when either speed or density is red
Yellow = when both speed and density are yellow
Orange = all other scenarios
How often will I receive alerts as a subscriber ?
Alerts are tuned to our 3 risk categories. We use the following formula to keep you informed at the right time, but not annoyed with too many notifications.
3 days straight in the red = a high risk notification is sent
5 days straight in the orange = a moderately high risk notification is sent
7 days straight in the yellow = a calm risk notification is sent
Every 14 days in the same risk category = an update notification is sent
What are the tick marks on the meters ?
These represent the same value one week prior. This gives you a quick way to see if your area is improving or getting worse since last week.
How often is your data refreshed ?
Our data is refreshed early each morning around 2:00 AM CST. While public Covid-19 data is typically updated around 11:00 AM CST, we lag behind this schedule about 14 hours because this gives us the time needed to send alerts to our subscribers during reasonable hours. We don't want to send alerts at inconvenient times.
Can I monitor multiple counties (i.e. family and friends) ?
Yes! There are two ways. From your county's status page, click the 'Compare' button to compare multiple counties. You can also pin multiple counties to your mobile device's home screen or your PC's desktop using standard browser shortcuts. You can also switch locations directly from your county's status page.
Will you be adding features to Covid Fire ?
Only features that are practical for the general public. While we do have connections in both the medical and research communities from which we seek guidance, we don't want to enter medical territory. Everyone should talk to their doctor about their own Covid-19 related fears, symptoms, and treatments. Otherwise, we welcome your feedback and suggestions. You can reach us via our contact page.
Why do you need to know my mobile carrier when subscribing ?
Since the pandemic impacts everyone, we have made Covid Fire a free public service. However, there are real costs for us. Among these is the expense of sending SMS ('text') alerts to your mobile device. With the large number of alerts we deliver each day, this cost would be prohibitive. However, by telling us your mobile number and carrier, we can send these same SMS alerts to you via a special email address for your mobile device. By sending alerts to you this way, our cost becomes manageable. This is the same SMS alert experience for you, but far less cost for us. We appreciate your cooperation.