The North American Monsoon (NAM) – Posted on April 27, 2024

April 27, 2024Posted inClimateNo Comments

In this article, I am presenting information from the National Weather Service and some other parts of NOAA on the North American Monsoon (NAM) which really is the Sonoran Monsoon but we wanted to have our own so we appropriated it. When the Sonoran Monsoon leaks into the U.S. it is called the NAM. The quoted material is indented and my comments are in boxes.

Yes and no.  Yes, it is a season not a single storm. Tucson NWS is Monsoon Headquarters and they had criteria for determining when the Monsoon started and stopped but it was felt that these were too complicated for Americans so they changed to a calendar start and stop time which works well.

The starting point for understanding the NAM or pretty much anything in Meteorology is to think about the time of the year. In the winter, the prevailing westerlies and the jet stream dominate weather in the CONUS. In the summer they still have an impact but other mechanisms can come into play.  No time in this article to explain it but the ITCZ moves to the north.

I would like to add that the differential heading of land and water in Mexico causes moist air to rise creating thermal low which kind of shoves the high north of it to the north. The mountains also play a role in sometimes blocking air flows and uplifting air masses which causes precipitation. It is quite complex but we are going to simplify it a bit in this article.

This map shows the percentage of annual precipitation that arrives during the Monsoon Season.  You can see that the NAM is very important to  Arizona, New Mexico, Kansas,  Western Texas, and the small part of Southeast California. But it is important to many other states as well. It may not provide a disproportionate part of their annual precipitation but a good monsoon versus a poor monsoon has an impact on many states.  As you can see, it is even more important to Mexico.

There are more than four types but these are the main ones.  We will go into detail on each of them in the body of this article. But it is really simple when you think about a high being clockwise and a low being counterclockwise.  Where you have a low west of a high, the air will be shuttled to the north from Mexico. So first look for the position of the main high-pressure area. Then look for where the low is. You will be able to figure out which way the wind will be blowing. If it is coming from where moisture is, it is likely to rain.

Some readers will need to click on “Read More” to get to the body of the article.

Oklahoma Drought Report – Posted on April 20, 2024

April 20, 2024Posted inClimateNo Comments

There were two presentations in this webinar. I am reporting on one of them in this article but I provide a link to the recording of both presentations. The second presentation also was of great interest.

I watch or receive a large number of webinars each month. They are all great. I was just blown away by Gary’s graphics so I could not resist publishing them.  Katie’s presentation is also great since it deals with a very important subject. I will probably write an article on her work also but there are only so many hours in the day and the number of interesting weather and climate topics is quite large. What follows in this article are many of Gary’s slides and one additional NOAA graphic that I added. My comments are in boxes like this. I provide a link to both presentations and if you watch that recording you will hear Gary’s comments on his slides. If I recall correctly, his presentation runs for about twenty-five minutes.

NOAA Sees No Sign of Greenhouse Gases Increases Slowing in 2023 – Posted April 6, 2024

April 6, 2024Posted inClimate1 Comment

Not a surprise but worth keeping track of and it is an interesting summary. I have published Theo Stein’s post in full and added some of my comments in boxes below some of the graphs and I added a paragraph explaining the Keeling Curve.

 

Some may need to click on “Read More” to read the rest of this interesting article

Is ENSO Static? Are they all Alike? Is there a Trend? – Posted on April 3, 2024

April 3, 2024Posted inClimate2 Comments

There was a very interesting blog post on ENSO.Gov that tries to assess this El Nino in the context of other El Ninos and I think they have done a very good job. I have reproduced the blog post in this article. Those who want access to any comments that have been submitted to that blog post can find the post HERE. Remember that all posts on the Climate.Gov ENSO Blog are attributed to the author who in this case is Nat Johnson. All the ENSO Blog posts are excellent. This one is beyond excellent.

The above shows that the current El Nino which is winding down has been pretty close to what would be expected from a typical El Nino. It also shows how both the typical El Nino and the current El Nino compare to Normal or Climatology. You can easily see the differences. The analysis is for the Meteorological Winter months of December through February.

There is a lot more to this blog Post so some readers will need to click on “Read More” to access the rest of this very interesting analysis.  If you accessed this article via the url you will already have the full article and will not need to click on “Read More”.

Climate context of the February 2024 megafire outbreak in Texas – Published March 14, 2024

March 14, 2024Posted inClimateNo Comments

Texas had some bad wildfires and Global Warming might have contributed to their problem.

I have reproduced the body of a Climate.Gov post on this and you can access the full article with comments HERE. But I have reproduced most of the article so you can find it in this article.

Some may need to click on “Read More” to be able to read the body of the article.

Northern Great Plains Response to Global Warming: Posted March 2, 2024

March 2, 2024Posted inClimate1 Comment

This is about the U.S. National Climate Assessment Program and in particular the Fifth U.S. National Climate Assessment which you can access HERE.

It is a long report and one part of the report is chapters on different regions of the U.S.   Last week I participated in a video Zoom session related to Chapter 25: the Northern Great Plains. So in this article, I will talk first about the National Climate Assessment (NCA) Program and then what I learned at the video session with the working group for the Northern Great Plains. After the discussion of the overall program, I will be using the slides presented at that session which are mostly from the National Climate Assessment report. I am using their slides because they presumable presented the slides that were of most interest to them and of course, there was only one hour for the session so that limits what can be presented.  If you do not like looking at slides without audio, you can access the Zoom session that was held HERE.

Introduction

 

This is important. Each Regional Chapter is organized around five topics and you will see them in this presentation.

Please click on “Read More” to access the discussion concerning the Northern Great Plains Region. It is presented in the form of responses to five key messages from the NCA5 Report.

Ice Coverage Nearly Nonexistent Across the Great Lakes, as the Historical Peak Approaches: Posted on February 27, 2024

February 27, 2024Posted inClimateNo Comments

This article is mostly excerpted from a post by Haley Thiem on Climate.Gov which you can access HERE. I am calling it Global Warming News but it may just be natural variation. But I think we should look at this as possibly related to Global Warming.

 Author’s Note: This is a typical graphic used in meteorology and hydrology. The individual years are shown but may be difficult to see as they are faint but the average of the prior 50 years is clearly visible.  The blue line shows this year to date (February 15, 2024). It is clearly unusual. Is it unusual enough to conclude that it is outside of the range of Post Industrial Revolution Climate? I do not know. If this pattern shows up a few more times some will draw that conclusion. And for sure the winter is not yet over and I think it is snowing there right now.  Whether it is cold enough for ice to form I do not know. Since we are comparing the current to a 50 year average, I have categorized this as climate rather than weather but others may see it differently.

To read the remainder of the article most will need to click on “read more”

Increasing Prevalence of Hot Drought Across Western North America Since the 16th Century: Posted February 26, 2024

February 26, 2024Posted inClimateNo Comments

In this case, the actual paper is available to be read. This should always be the case. If the U.S. Government is paying for research that research should not be behind a paywall. It is not the role of the U.S. government to create business opportunities for publications. I think that doing so is illegal. In this case, the full paper is open source and I provide the introduction to the paper and the link to get the full download. It is not easy reading.

To read more most will need to click on “Read More”. This is not a new finding but it supports some earlier papers some of which we have reported on. It is not a pretty picture and it is somewhat surprising as warmer water should in theory create a wetter atmosphere but during drought, the soil dries out and this seems to be happening more often than in the past so it is one more negative impact of Global Warming.

An Unexpected Decline in Spring Atmospheric Humidity in the Interior Southwestern United States and Implications for Forest Fires: Posted on February 24, 2024

February 24, 2024Posted inClimateNo Comments

I think this is about Global Warming But I am not sure. NOAA funds or partial funds research but then you have to pay to see it and for sure to publish it which I think is illegal but that is how the government works.

This appears to be very important.  It would have been nice to have access to the full paper but one can buy a copy for not a lot of money.

Corresponding author: Tess W.P. Jacobson, tessj@ldeo.columbia.edu

Image credit: Pixabay

To read more you probably have to click on “Read More”.

Weather is Not Climate February 10, 2024

February 10, 2024Posted inClimateNo Comments

What is the difference between weather and climate?  It is quite complicated and quite frankly arbitrary and I personally do not like the NOAA definition of climate but this blog post sheds a little light on the subject.

It was posted in late January and it contains three short YouTubes you can watch that show how averaging turns weather into climate. It is not as precise as I would like but it at least starts the conversation. The post was written by Michelle L’Heureux

As many of the ENSO Bloggers do from time to time they intertwine the science with personal experience which may help in understanding the concept.

The official NOAA definition of Climate is the average over the last three completed decades so currently that is 1991 -2020. I do not like that definition because it does not reflect the influence of long cycles such as the AMO and PDO but I can not think of a better definition.

You can read the Blog Post with the comments HERE   But I have reproduced most of the post in this article with some of my comments so click “Read More” to read my article.