<![CDATA[PM2.5 Noticeable Discrepancy with Live Data?]]>Hi Windy Folks,
I'm looking to better understand the PM2.5 model and whether it's accurate.
Today is a typical day in Southern California and has been for a while. No wildfires nor other anomalies to drastically skew the predictions.
I overlaid the current PM2.5 prediction with the PM2.5 live data using the PM2.5 layer and the "Air Quality" toggle as shown below.

test1.jpg

Here is the data overlaid and both layers are synced to the current time:

photo_2023-06-14_15-01-55.jpg

I compared the values of the live readings with the faded colors and scale of the prediction. Based on the color scale at the very bottom of the image, the prediction appears to suggest the max PM2.5 is about 15-20 microg/m3. The live data, however, suggests a good portion of the map should be light to dark orange instead.

Will someone help me understand this discrepancy?
Thank you!

]]>https://community.windy.com/topic/26160/pm2-5-noticeable-discrepancy-with-live-dataRSS for NodeMon, 15 Jun 2026 05:38:14 GMTWed, 14 Jun 2023 22:24:47 GMT60<![CDATA[Reply to PM2.5 Noticeable Discrepancy with Live Data? on Thu, 15 Jun 2023 17:59:10 GMT]]>@idefix37 Thank you for your response. Durr, I missed that the number shown for the AQI was not the same as the particulate matter value.

]]>https://community.windy.com/post/147405https://community.windy.com/post/147405Thu, 15 Jun 2023 17:59:10 GMT<![CDATA[Reply to PM2.5 Noticeable Discrepancy with Live Data? on Thu, 15 Jun 2023 13:19:56 GMT]]>@Colter-Cederlof
Hi,

Here is what you read about the data used for the PM2.5 layer based on satellite measurements.

9696FF82-9725-45C6-8D73-D53BC09DBA2B.jpeg

In the area you mention there is not a huge discrepancy.

00F1515E-D220-4664-A299-861693C69A99.jpeg

But locally in some valleys the Air quality stations show higher PM2.5 concentration for the reasons explained above.

Note the Quality Index and the color shown at Air quality stations are not only in relation with PM2.5 but with the pollutant showing the worse concentration.

]]>https://community.windy.com/post/147315https://community.windy.com/post/147315Thu, 15 Jun 2023 13:19:56 GMT