Short Term and Intermediate-Term Weather Outlooks for the U.S. and a Six-Day Forecast for the World: posted September 18, 2023

Here is what we are paying attention to in the next 48 to 72 hours. The article also includes weather maps for longer-term outlooks and a six-day World weather outlook.

We start with the U.S. Information. You can update this section here but these are 48 to 72-hour forecasts so if I have not been able to update this area twice daily, what is shown is still valid and the images in the body of the article update automatically but sometimes they are a bit slow to update.

Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
Mon Sep 18 2023
Valid 12Z Mon Sep 18 2023 – 12Z Wed Sep 20 2023

…Heavy rainfall with localized flash flooding possible for New England
Monday…

…Heavy rain and severe storm chances return to parts of the Southern
Plains on Tuesday…

…Hot late Summer temperatures for the heartland to start the week…

Short Term and Intermediate-Term Weather Outlooks for the U.S. and a Six-Day Forecast for the World: posted September 17, 2023

Here is what we are paying attention to in the next 48 to 72 hours. The article also includes weather maps for longer-term outlooks and a six-day World weather outlook.

We start with the U.S. Information. You can update this section here but these are 48 to 72-hour forecasts so if I have not been able to update this area twice daily, what is shown is still valid and the images in the body of the article update automatically but sometimes they are a bit slow to update.

Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
319 PM EDT Sun Sep 17 2023
Valid 00Z Mon Sep 18 2023 – 00Z Wed Sep 20 2023

…Shower and storm chances along the East Coast confine to New England on
Monday…

…Unsettled weather and severe storm chances return to parts of the
Southern Plains on Tuesday…

…Much above average high temperatures spread from the Northern Rockies
to the Northern Plains early this week…

Looking Back at the Global Climate in August 2023 – This past August was the Warmest August on Record. But it was More Than That – September 16, 2023

Every month, John Bateman sends me a nice email. Usually, he sends me two: one about the U.S. and one about the world.  I do not recall receiving an email from him on the U.S. but I published my own article on August in the U.S. and you can find it HERE. Yesterday he sent me the email for the world. Since they are emails, I usually can not provide a link to what he sent me. He is a spokesperson (not sure that is the right description of his job) for NOAA both NCEI and other parts of NOAA.  For this monthly article, all of the information in his email comes from the NOAA National Centers for Environmental Information so the information he includes in his email and much more can be found HERE. I published his article in full but included two additional graphics from NCEI namely the historical year by year record and the map of important events.

Obviously the headline this month is that August has been the warmest August since this data has been collected.  And it was also the fifth consequtive month of record ocean surface temperatures.

 

This is the record of August land and ocean temperature anomalies and this Augugust appears to have set a new record high. It is just speculation on my part but I think it is the stepwise rise in temperature we get with an El Nino. But some believe that other factors were a larger contributor to this in August and also in July than simply the increase in greenhouse gases. They may be correct in that many factors impact temperature and precipitation. In this article, we report what happened rather than try to explain why it happened. “Attribution” is always very complex.

 

Short Term and Intermediate-Term Weather Outlooks for the U.S. and a Six-Day Forecast for the World: posted September 16, 2023 – Hurricane Lee Arrives

It is now Post-Tropical Cyclone Lee rather than Hurricane Lee with the change occurring right after I published so I could not change the title of the article.

Here is what we are paying attention to in the next 48 to 72 hours. The article also includes weather maps for longer-term outlooks and a six-day World weather outlook.

We start with the U.S. Information. You can update this section here but these are 48 to 72-hour forecasts so if I have not been able to update this area twice daily, what is shown is still valid and the images in the body of the article update automatically but sometimes they are a bit slow to update.

Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
Sat Sep 16 2023
Valid 12Z Sat Sep 16 2023 – 12Z Mon Sep 18 2023

…Tropical storm conditions for coastal New England today as Lee tracks
by…

…Shower and storm chances this weekend from the Southern Plains to the
Southeast/Mid-Atlantic with some locally heavy rainfall possible…

…Much above average highs expected for the Pacific Northwest/Northern
Rockies this weekend with a Critical Risk of Fire Weather Saturday…

cone graphic

[Key Messages]

NOAA Updates its ENSO Alert on September 14, 2023 – The El Nino Advisory Continues. In a Week, NOAA Will Update us on how this Impacts U.S. Weather

On the second Thursday of every month, NOAA (really their Climate Prediction Center CPC) issues its analysis of the status of ENSO. This includes determining the Alert System Status.  NOAA again describes their conclusion as “ENSO Alert System Status: El Nino Advisory”

There is not much doubt that we have an El Nino. How long it lasts and its strength remains to be seen. NOAA may be more conservative compared to some other Weather Advisory Organizations.

CLIMATE PREDICTION CENTER ENSO DISCUSSION

The second paragraph is what is important:

“The most recent IRI plume indicates El Niño will persist through the Northern Hemisphere winter 2023-24.  Despite nearly the same ensemble mean amplitude as last month, the shorter forecast horizon means that the odds of at least a “strong” El Niño (≥1.5C for the November-January seasonal average in Niño-3.4) have increased to 71%.  However, a strong El Niño does not necessarily equate to strong impacts locally, with the odds of related climate anomalies often lower than the chances of El Niño itself (e.g., CPC’s seasonal outlooks).  In summary, El Niño is anticipated to continue through the Northern Hemisphere winter (with greater than 95% chance through January – March 2024; ).”

We now provide additional detail but I am keeping this article shorter than usual because nothing much has changed since last month.

CPC Probability Distribution

Here are the new forecast probabilities. This information in the past has been released twice a month and the first release is based on a survey of Meteorologists, the second is based on model results. The probabilities are for three-month periods e.g. ASO stands for August/September/October. The approach may have changed as IRI (The International Research Institute for Climate and Society, Columbia University Climate School) may no longer be involved.  Their website has not been updated this month.

Here is the current release of the probabilities:

You can clearly see the forecast does not extend beyond AMJ 2024 and one does see a tail-off in the probabilities for El Nino conditions in the Eastern Pacific after the winter season.  Some Meteorological Agencies see El Nino lasting longer but JAMSTEC showed it ending sooner in the article I posted last night which you can access HERE.

Here is the forecast from late last month.

This showed a slower demise of the El Nino.

Select Short Term and Intermediate-Term Weather Outlooks for the U.S. and a Six-Day Forecast for the World: posted September 15, 2023 – Hurricane Lee is Still a Factor

Here is what we are paying attention to in the next 48 to 72 hours. The article also includes weather maps for longer-term outlooks and a six-day World weather outlook.

We start with the U.S. Information. You can update this section here but these are 48 to 72-hour forecasts so if I have not been able to update this area twice daily, what is shown is still valid and the images in the body of the article update automatically but sometimes they are a bit slow to update.

Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
Fri Sep 15 2023
Valid 12Z Fri Sep 15 2023 – 12Z Sun Sep 17 2023

…Lee continues tracking north, tropical storm and hurricane conditions
possible for coastal New England Friday and Saturday…

…Heavy rain and strong storms likely over the Southern Plains Friday…

…Dry conditions in the West with some much above average highs expected
for the Pacific Northwest/Northern Rockies this weekend...
cone graphic

[Key Messages]

Our Report on the JAMSTEC Three-Season Weather Forecast – September 14, 2023

The Japan Agency for Marine-Earth Science and Technology, or JAMSTEC, is a Japanese national research institute for marine-earth science and technology

From the JAMSTEC Discussion:

As predicted, the recent observation confirms the occurrence of the El Niño. The SINTEX-F ensemble mean predicts that the El Niño will reach its peak in the late boreal autumn and persist at least until the next boreal spring. However, there is a large uncertainty in the predicted amplitude.

Although it is a World forecast, it includes a forecast for North America since North America is part of the World. The JAMSTEC discussion does not address it but the maps show the U.S. being an area that has a lot of area that is not warmer than Climatology which I interpret as a fairly cold winter but surprisingly dry in the Southwest.

First, we take a look at the forecasted sea surface temperature anomalies (SSTA). JAMSTEC starts by forecasting the SSTA and Nino 3.4 Index on the first day of the month and from there it usually takes their models about two weeks to produce their seasonal forecast. I received it from JAMSTEC on September 12, 2023 which is a week earlier than when we will receive the Seasonal Outlook from NOAA which will be on September 21.  The JAMSTEC model runs are based on conditions as of September 1, 2023. The NOAA Seasonal Outlook will be based on conditions closer to the time when it is issued.

 

Short Term and Intermediate-Term Weather Outlooks for the U.S. and a Six-Day Forecast for the World: posted September 14, 2023 – Hurricane Lee is Still a Factor

Here is what we are paying attention to in the next 48 to 72 hours. The article also includes weather maps for longer-term outlooks and a six-day World weather outlook.

We start with the U.S. Information. You can update this section here but these are 48 to 72-hour forecasts so if I have not been able to update this area twice daily, what is shown is still valid and the images in the body of the article update automatically but sometimes they are a bit slow to update.

Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
Thu Sep 14 2023
Valid 12Z Thu Sep 14 2023 – 12Z Sat Sep 16 2023

….As Lee continues to track north, tropical storm conditions are
possible across a large portion of coastal New England beginning Friday
night…

…Life-threatening storm surge flooding possible in portions of
southeastern Massachusetts beginning late Friday…

…Unsettled weather, with heavy rain and strong storms possible, to
continue into the weekend over the southern Plains…

cone graphic

Short Term and Intermediate-Term Weather Outlooks for the U.S. and a Six-Day Forecast for the World: posted September 13, 2023

Here is what we are paying attention to in the next 48 to 72 hours. The article also includes weather maps for longer-term outlooks and a six-day World weather outlook.

We start with the U.S. Information. You can update this section here but these are 48 to 72-hour forecasts so if I have not been able to update this area twice daily, what is shown is still valid and the images in the body of the article update automatically but sometimes they are a bit slow to update.

Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
Wed Sep 13 2023
Valid 12Z Wed Sep 13 2023 – 12Z Fri Sep 15 2023

….Showers and thunderstorms are likely, with heavy rainfall and flooding
possible, across portions of the southern Plains over the next few days…

…More heavy is rain likely, with possible flooding, for portions of the
Northeast today…

…Dangerous surf and rip current conditions to spread north along the
East Coast over the next couple of days…

cone graphic

Looking Back at August 2023 in the U.S. September 12, 2023

Usually for this article where I provide a review of the prior month, I reproduce John Bateman’s email in its entirety.  But John Bateman has not yet sent out his email because NCEI has not yet published their review of August 2023.  I suspect the delay is due to the Labor Day weekend but there may have been other factors.  But I also like to add a few additional graphics, namely the state ranking maps after John Bateman’s email. These maps show how temperature and precipitation for each state rank relative to the 129 (article originally mistakenly said 139) years of what is considered to be the most reliable data we have.

That information became available today so I am publishing it tonight. When NCEI issues their report and if John Bateman sends me his email, I will publish it or the NCEI report which is the basis for John Bateman’s email separately.

Now we will discuss the State Rankings for the single month of August 2023.  Let me remind you that this shows where the Temperature and Precipitation in August rank within the 129-year history of that state. It is a good way to put August in perspective.

Three states set records for average temperature. That is a lot. Many others were much above average.

But only two states set a record for the maximum temperatures.

The same two states set a record for the highest minimum temperatures usually meaning there was a lot of humidity.  There were a lot of states that were much above average but not always the same states that were much above average in the first measure and graphic which is average temperature. It can get a bit confusing. High minimum temperatures mean a high use of air conditioning and for people without air conditioning, uncomfortable nights.

One state set a record for being the driest in its history. However, there were many states that had much above-average precipitation.