Wednesday, October 30, 2019

2019 wildfire season: extreme fire danger in southern California (October 30th)

Yesterday I wrote about the dangerous fire weather that will occur in portions of California through tonight (Wednesday, October 30th or tomorrow (Thursday, October 31st). The timing on the end of the dangerous fire weather (Red Flag and High Wind Warnings) varies by Weather Forecast Office.

I am holding all in southern California who are currently experiencing these dangerous fire weather conditions in my meditations: firefighters on the ground and in the air battling these blazes, other first responders and emergency relief workers, all who have lost their homes or businesses, those who are evacuated, livestock and other animals, meteorologists in NWS Weather Forecast Offices, and anyone else that I am not naming here.

I feel wholly inadequate in writing this blog article today. I opted not to try to write about the wildfires that are cropping up in California today, nor am I going to report on wildfires that I have written about the last couple of days.

I was not quite sure what to write about today. I decided to focus on the current weather in southern California that are contributing to the high fire danger, winds and humidity. At the very least, I want to offer this post so that all affected who might read this at some point know that I was paying attention. I knew about the National Weather Service Weather & Hazards Data Viewer (takes you to viewer for the Los Angeles California area) from my wonderings on various National Weather Service (NWS) websites. I went to the viewer and loadedL Red Flag Warnings, wind speed and direction. wind gusts, and humidity. I copied a screen image for you at about 3:25 PM EDT this afternoon. You will see a graphical notation for wind speed and direction that may be referred to as a wind barb, some of you will be familiar with wind barbs but if you want a refresher (I did), a friend from the NWS Mt. Holly Weather Forecast Office sent me some good information about wind barbs including a nice graphic and a definition that may be helpful, it may be found here.

The screen image is below.  The numbers in green are the humidity, note how low they are with little water vapor in the air in some places. The numbers in red are wind gusts, with the wind barbs indicating wind speed and direction. Humidity readings are represented by the green numbers, note how low (little water vapor in the air) many of the readings are. The areas colored in red are Red Flag Warnings, go here for more information on Red Flag Warnings. Red Flag Warnings indicate low humidity, high winds and dry fuels with exact criteria varying by Weather Forecast Office. You should be able to click on the image to get a bigger picture. I bookmarked the link I used to get the map for you. Caution is advised in looking at the link because I believe that what you see at this link will change over time, so what you see may be different.

Screen Shot taken at 3:25 PM EDT on October 30, 2019















You may want to see some wind speed information in tabular format, thanks to the folk at the Iowa State University Iowa Environmental Mesonet for their great archives of current and past text products from NWS Weather Forecast Office, I can give you good permanent links to the latest high wind speed data from NWS Los Angeles and NWS San Diego. Note that there are several observations from both Weather Forecast Offices of 55 mph and above. These data may be preliminary.

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