California

yuiyoshida

(41,831 posts) Tue Nov 13, 2018, 12:37 PM Nov 2018

Just got another alert on my cellphone, another "Red" bad quality air day

With the fires, my delivery guy was wearing a surgical mask this morning again. Message as follows:
AIR QUALITY index red (Unhealthy)for older adults, kids and those with heart/lung disease should stay in doors and avoid outdoor activities. www.sf72org.

Yup, another crappy air day, due to the fires in California! Stay safe Fire fighters and first responders!

3 replies

= new reply since forum marked as read

Highlight:

Just got another alert on my cellphone, another "Red" bad quality air day (Original Post) yuiyoshida Nov 2018 OP

Some schools near San Diego are closed and power has been cut to residents BigmanPigman Nov 2018 #1

I read on a D.U. post a coupl'a days ago, humidity was .02%. Is that possible? 3Hotdogs Nov 2018 #2

How do you get a negative dew point? billh58 Nov 2018 #3

BigmanPigman

(51,584 posts)

1. Some schools near San Diego are closed and power has been cut to residents

Reply to yuiyoshida (Original post)

Tue Nov 13, 2018, 02:36 PM

Nov 2018

as a precaution. The winds were over 60 MPH in some places and it is super DRY!

Another fire was started by a chain dragging under a person's car of the frreway that caused sparks. This is the second time in three days this has happened. Fortunately both fire were put out quickly. It just shows how easily anything can start a fire.

3Hotdogs

(12,370 posts)

2. I read on a D.U. post a coupl'a days ago, humidity was .02%. Is that possible?

Reply to yuiyoshida (Original post)

Tue Nov 13, 2018, 03:01 PM

Nov 2018

Last edited Tue Nov 13, 2018, 05:21 PM - Edit history (1)

Correction: 2%

billh58

(6,635 posts)

3. How do you get a negative dew point?

Reply to 3Hotdogs (Reply #2)

Tue Nov 13, 2018, 04:37 PM

Nov 2018

There isn't any special physical significance of a negative temperature or dew point on the Fahrenheit scale. Just as a temperature of -2 F is simply four degrees colder than a temperature of +2 F, a dew point of -2 simply means the air is a little drier than air with a dew point of +2.

https://www.wral.com/weather/blogpost/1201076/?comment_order=forward

Negative dew point causes negative humidity.

Reply to this discussion