My 2023 Summer Outlook for the Northeast and Northern Middle Atlantic Region.

 

What does this summer look to bring us? To prepare for the months ahead, here is my Northeast Summer Forecast.

To develop the summer forecast, I analyzed a range of factors, including a variety of analogues, sea- surface temperatures, and other information. This year, the ENSO (El Nino) pattern and water temperatures in the north Pacific Ocean are looking to be major factors affecting this summer’s temperature and precipitation outlook.

 

This Spring…

Despite several cooler than average days so far in April, those periods of record-breaking summerlike temperatures have resulted in April as a whole, being overall above average across the region. Seeing temperatures that warm is very rare, the pattern doesn’t support sustained temperature that high until we get into June.

 

Right now, it looks like May as a whole, will be overall average to slightly below average. But this time of year, slightly below average temperatures doesn’t have that much of an impact, so it will still be very springlike.

 

El Nino…

The Climate Prediction Center/NCEP/NWS has us in an El Nino Watch. This is the Warm Phase (Positive Phase) of the El Nino Southern Oscillation (ENSO).  

Historically when the CPC places us in an El Nino Watch, an El Nino developed half of the time. So, while El Nino is likely, the issuance of a Watch is no guarantee that it will develop.  

There is significant amount of warmer than average Sea Surface temperatures and Sub surface water temperatures in the equatorial Pacific. The SST anomalies continue to strengthen in the tropical eastern Pacific. Those very warm SST off the West Coast of South America will continue to push west into the Central Equatorial Pacific for June and July. East based El Nino's are typically warmer than their central based (modoki) counterparts. So how the El Nino ends up (if it does) developing will have a lot to say about temperatures. But based on what I'm seeing, I'm leaning toward the idea of a very strong El Nino by the time we get closer to the coming Winter.  

The Southern Oscillation Index (SOI)

When we look at the Southern Oscillation Index (SOI) index numbers. Negative numbers tilt toward El Nino which creates weaker trade winds over the Pacific. When the numbers are positive, they tilt toward La Nina which creates stronger trade winds over the Pacific.

As of this writing, the 30-day average is at -1.76.

The Pacific Decadal Oscillation (PDO)…

We currently have a warm blob in the western North Pacific. At the same time, we have cooler than average SST off the West Coast of North America. This places us in the cool phase (negative phase) of the PDO. 

 

The PDO has a big influence on the ENSO. If the PDO is in the same phase as the ENSO their Associated impact can be amplified. However, if they’re not in the same phase the associated impact can be reduced.  

Here is a chart showing the PDO index phase shifts from January 1854 Through March 2023.

Quasi-Biennial Oscillation (QBO)

This summer will likely feature a negative QBO. Typically, a negative QBO sets up ridging in the west, with a trough in the east, making a pattern where the Northeast has to deal with persistent upper-level lows impacting the region. A negative QBO also tends to lend support for predominate negative North Atlantic Oscillation (NAO) and negative Atlantic Oscillation. This would mean we could have higher odds of seeing high latitude blocking. While this would make for a great winter pattern, for snow lovers; it wouldn't be a good pattern for summer weather lovers. 

Analogues…

Here are the analogues I’m using for my 2023 Summer Outlook

1963, 1965, 1976, 1982, 1986, 1997, 2009, 2015

500mb Geopotential Height Composite Anomaly 1991-2020

 

The combined Composite years Geopotential Height Composite Anomaly for Jun – Aug

The individual analogue years Composite June through August Temperature Anomalies

The combined Composite years Temperature anomaly for Jun – Aug

 

The individual analogue years Composite June through August Precipitation Anomalies

The combined Composite years Precipitation anomaly for Jun - Aug

 

1963 was a moderate El Nino, 1965 was a strong El Nino, 1976 weak El Nino, 1982 very strong El Nino, 1986 was a moderate El Nino, 1997 was a very strong El Nino, 2009 was a moderate El Nino, 2015 was a very strong El Nino

1963 was a moderate cool phase, 1965 was a moderate cool phase, 1975 moderate to strong cool phase, 1982 was a weakening moderate cool phase, 1986 was a strong warm phase, 1997 was a very strong warm phase, 2009 was a moderate cool phase, 2015 was a moderate to strong warm phase.

When we look at the analogue years. We can see  El Nino and the PDO do have a temperature and precipitation correlation.  The Northeast and Middle Atlantic tend to be quite warm when both the ENSO and PDO are strongly positive.  When the ENSO and PDO are in opposite phases, the farther they are apart the colder the CONUS becomes. 

 

Temperatures…

 

Those well above average SST anomalies off the East Coast, should keep the Middle Atlantic and Southern New England Closer to the Coast warmer than the interior parts of the Northeast.

The middle Atlantic and southern New England should see overall temperatures averaging out to average to slightly below average. While interior areas of northern New England, New York State and Pennsylvania end up with overall temperatures averaging out slightly below average to below average.

  

Precipitation…

While the current soil moisture levels across the Middle Atlantic Region are quite low

With the overall precipitation setup that looks to unfold starting on today the 29^th and going into next week, we should see at least a partial recovery of the drought conditions over the Middle Atlantic into Southern New England for this Summer.  

 

Palmer Drought Severity Index

 

 

Precipitation looks to be largely average to slightly above average across western and central New York State and western Pennsylvania, while northern and eastern New York State, eastern Pennsylvania, New England and the Middle Atlantic end up averaging above average to well above average.

This doesn't mean we won't see any really hot days this summer. It just means we should trend toward overall cooler temperatures over the three month period. The same goes for Precipitation, during El Nino the Northeast and Middle Atlantic Region tend to see wetter summers. But that doesn't mean we won't see some dry stretches. This is all about climatical averages. 

Well that's it. Hope you enjoyed reading this.  

 

 

 

 

My 2023 Atlantic Hurricane Outlook Part Two

 

Here is part two of this year’s hurricane outlook. Part two will go more into the developing El Nino, other major weather outlet forecast, the cone of uncertainty, and other changes being implemented by the National Hurricane Center.  

 Refer to part one for definitions and acronyms.

Part One

My analogue seasons…

 1957,1965,1972,1982,2002,2009,1997, 2015

1957

 

1965

 

1972

 

1982

 

1997

 

2002

 

2009

 

2015

 

 

Typically, the analogues saw generally 6-10 named storms with very low seasonal ACE points.  This is something I will come back to.  

 

Sea Surface Temperatures (SST)…

ENSO

Over the last few weeks, upper ocean heat content has warmed rapidly.

SSTs are above average in the eastern equatorial Pacific, with SSTs in the central equatorial Pacific are near average.

Here is a look at Nino 1+2, Nino 3, Nino 3.4, and Nino 4 SST anomalies

 

The latest weekly

SST departures are:

Nino 4 0.2ºC

Nino 3.4 0.1ºC

Nino 3 0.4ºC

Nino 1+2 2.7ºC

 

The subsurface water temperatures in the equatorial Pacific Ocean are now dominated by positive temperature anomalies.

The Climate prediction Center /NCEP has issued an El Nino Watch

In part one I said the coming El Nino should be moderate to strong. Looking at the current SSTs in the Equatorial Pacific, we can see conflicting signals. Spring is a difficult time to forecast the ENSO, for this reason it is labeled the Spring Predictability barrier  

 

Pacific Decadal Oscillation (PDO)

We do have a warm blob in the western North Pacific.

With SST just off the West Coast of North America are cooler than average.

 

Currently our developing El Nino and the PDO are at odds with each other. When we look at the Ocean Current chart, we can see how the current off the Western North American Coast travel south where they mingle with the current in the Equatorial Pacific. As a result, as the two current compete, we have El Nino conditions in Nino 1+2, with neutral ENSO conditions in Nino 3.4. 

When we look at the Southern Oscillation Index (SOI) index numbers. Negative numbers tilt toward El Nino which creates weaker trade winds over the Pacific. When the numbers are positive, they tilt toward La Nina which creates stronger trade winds over the Pacific.

Trade wind anomalies over the next month over the Nino 3.4 region. The blues and greens indicate strong trade winds. The yellows and oranges indicate weaker trade winds. The chart shows trade winds will be generally average, with a burst of stronger winds. We need weaker trade winds if we want to see those warm subsurface waters to make their way to the surface in a big way.

So, we’re likely to experience El Nino this Summer. But the question still remains on how strong the El Nino will be. The strength of the La Nina will determine how much sinking air we see over the Atlantic Basin this hurricane season.

Here is a graphic that shows the typical areas of rising and sinking air during El Nino. Sinking air is very hostile when it comes to tropical cyclone formation. 

 

Some of the models, like the Euro do show a Super El Nino developing. But most show moderately strong to strong.

Atlantic Basin

SSTs are well above average in the eastern tropical and subtropical Atlantic. SST are also well above average off the East Coast in the Western Atlantic and the Gulf of Mexico. The SST are 10 degrees above average in parts of the Gulf of Mexico and near average in the Caribbean. With the MJO rotating through the favorable phases 8 and 1 along with those very warm SST in the Gulf. I wouldn't be surprised if something tropical spins up in the Gulf before the official start of the hurricane season.   

 Five of the analogue years were strong El Nino’s with two of the analogues being fairly strong moderate seasons. But all of those years typically saw cooler SST in the tropical and subtropical Atlantic.  But when we look back at the SST chart, we can see this year the SST in the tropical and subtropical Atlantic are abnormally warm. This is another conflicting signal for the number of possible named storms in the Atlantic this hurricane season.    

 Other Outlets hurricane outlook forecast...

 Colorado State University (CSU) is predicting that the 2023 Atlantic hurricane season will be slightly below average with 13 named storms, 6 of them becoming hurricanes, with 2 of those becoming major hurricanes. CSU is also calling for an ACE of 100.

Accuweather’s outlook shows that the 2023 season will be near the historical average with 11 to 15 named storms. Four to eight of those named storms are expected to reach hurricane strength, with one to three of those hurricanes achieving major hurricane status.

WeatherBELL Analytics outlook is showing 10-14 named storms, with 5-7 hurricanes, 2-3 major hurricanes, with a seasonal ACE of 70-110.

 

The Cone of Uncertainty…

The cone of uncertainty is the projected track of the center and intensity of a tropical storm or hurricane. The cone is issued by the National Hurricane Center. The cone, is a series of imaginary circles placed along the future forecast track at 12,24,36 hours, etc. The size of each circle is set so that two thirds of the official forecast track errors over the previous five years falls within the circles.

The size of each circle grows larger with every 12- or 24-hour forecast interval because forecast errors in the position of a tropical cyclone’s center increase with time. This is why the cone of uncertainty, made up of those invisible circles, grows wider as the forecast goes farther into the future.

Before 2003 the cone of uncertainty only went out three days. But in 2003 the cone was extended out to five days. Forecast error has generally decreased for the last 10 years, due to improved model performance and better satellite data.  Over the last several years the cone of uncertainty has been two and five days. But with the increased confidence in the models and satellite data; starting this year the cone of uncertainty will now be two days and seven days. Due to the added length of time, the area showing where the storm may form on the map could show up larger than in the past.

This brings me to an important point. Many people get confused when they look at the cone of uncertainty; they focus on the cones center line, instead of the entire breadth of the cone. We saw this with disastrous and deadly consequences with Hurricane Ian last year. I really would like to see the NHC not show the skinny line at the center on any of their maps; I think it would make people pay more attention. We have to remember that tropical cyclones stray outside the cone roughly one third of the time

What the cone doesn't communicate are critical factors such as storm size, intensity, hazards or potential impact..

    

Other big changes the NHC is making in 2023…

The NHC will be adding Invest Numbers to this season’s outlooks. If you followed my tropical post, you have seen me, use Invest (I) 90 to 99, followed by a suffix letter "L". The L signifies the Atlantic Basin. Invest is used to indicate an area of interest that could develop into a tropical cyclone.  I think including the Invest numbers will make it easier for the general public to understand tropical forecast.

For the last two years, the NHC has used experimental peak storm surge graphics. Starting this season, the NHC will make the peak storm surge graphic operational. Since storm surge is the number on killer when it comes to landfalling hurricanes. This will hopefully make the danger more identifiable and reduce the number of fatalities caused by storm surge.

The NHC will also remove land based tropical cyclone watches and warnings from the tropical cyclone forecast advisory. But they will continue to issue the watches and warnings in the public advisory.

 

Summary…  

 

During El Nino there is a tendency for tropical cyclones not forming in Caribbean due to high shear in that part of the Atlantic Basin. If we look back at the analogue season graphics, we see most of these years saw no tropical cyclone activity in the Caribbean, with 2002 being the only outlier with two tropical cyclones that track through the Caribbean. So based on those analogues this year should see well below average activity in the Caribbean.  

  

Also, typically we see weaker than average wind shear over the Gulf of Mexico and off the East Coast in the Western Atlantic, for this reason tropical cyclone tracks could stay north of the Caribbean and form in the southern Gulf. The setup hints that there could be a lot of activity off the East Coast. We also should see above average activity out in the middle with the fishes.

We do look to see a fairly strong moderate to strong El Nino develop by the heart of the hurricane season So this will likely tamper down the number of tropical cyclones in the Atlantic Basin. This is what the Analogues do indicate. But due to the fact that the SST anomalies in parts of the Atlantic Basin are generally warmer than they typically are during an El Nino; is the reason I’m calling for slightly higher numbers of Tropical Cyclones to develop this season.

Pre season tropical activity is very likely in May in the Gulf of Mexico.

For now, I’m staying with my thought that this will be slightly below average to average season, with 10 to 14 named storms 4-7 hurricanes and 1 -2 major hurricanes.  The Seasonal ACE looks to be 60-90.

I released part one before the other outlets released their preliminary 2023 hurricane outlooks. So, seeing that they look similar to my numbers is making me more comfortable with my ideas.

Link for part 3