My spring outlook

This is later than I normally post the spring outlook. But every time I would start to work on it something came up. But beyond that, I’ve been going back and forth with the idea of even posting one at all. More than a few of Y’all used my winter outlook as cannon fodder, making me feel like a long tailed cat in a room of rocking chairs. But I’ve decided to go ahead and post it……

Meteorological spring began on March 1^st, with Astronomical spring beginning on Thursday March 19^th, at 11:49pm. We have already been experiencing above average spring temperatures. The question will that continue?

The three major reasons winter 2019-2020 was so warm.   Was the Eastern Pacific Oscillation (EPO), a near record-breaking positive Arctic Oscillation (AO), and the powerful Polar Vortex (PV). All three of these things kept the cold air locked up well to our north.  The same general atmospheric pattern that allowed for the mild winter, has continued into spring 2020. As we move forward, the strongly positive Arctic Oscillation and the strong polar vortex are going to be very big factors for this spring.
   

Here is my write up on why the winter acted the way it did.

Outlook Overview:

El Nino Southern Oscillation (ENSO):

So far, the ENSO is basically neutral (neither El Nino or La Nina). This will most likely stay the case heading into summer 2020.

The ENSO SST departures are warmer than average by a little over 1.0 C in Nino regions 4 and 1+2. With Nino region 3.4 coming in about half of that. Nino region was 0.1 C. That isn’t a cold signal for the East CONUS.

El Nino Southern Oscillation (ENSO) Current Status and Forecast

The Nov. 2019 – Jan. 2020 Oceanic Niño Index (ONI) of 0.6°C was in the weak El Nino range for the second consecutive month. Real-time sea-surface temperatures (SSTs) are near-to-above average across most of the tropical Pacific Ocean.  The Climate Prediction Center (CPC) is predicting SSTs to cool but remain in the ENSO-neutral range through this coming summer.  

Here is a look at the current ENSO status

The Madden Julian Oscillation (MJO):

Since November into December 2019, the MJO stayed primarily in the warm phases four, five, and six. But finely the MJO is looking to head into phases two and three; these are colder phases this time of year.  

The EPO:

The EPO is forecast to go very negative. This is a cold signal for the U.S, and is the opposite of what it did for winter 2019-2020. Because, typically it pushes colder Alaskan and Canadian air into the U.S pattern. The WPO is also looking to go negative, again this is a cold signal for the U.S. 

The Pacific North American teleconnection (PNA):

Currently the PNA is in a negative phase. This phase typically brings higher pressures (ridge) to the eastern US, and a trough to the western U.S. This usually brings a warmer and drier pattern for the eastern U.S.  But the PNA doesn’t really drive the pattern, it responds to other teleconnections in the Pacific, like the EPO.  So the with the EPO staying in a positive phase for most of winter 2019-2020, it’s no surprise that the PNA currently negative. It won’t happen immediately, but as the EPO turns negative, the PNA should respond and turn positive.  

The AO:

The AO is strongly positive this is a warm signal for the U.S.

The North Atlantic Oscillation (NAO):

This is the time of year, that the NAO exerts its greatest input on the atmospheric pattern.  After a brief dip into negative territory, it looks like it will head back into a positive phase which is a warm signal for the U.S.

The PV:

A warming event looks to occur in the Stratosphere next week. As I’ve said many times these sudden stratospheric warming events can affect the PV. If they weaken the PV, they can impact our weather here in the Northeast. The first warming wave will build north and enter the PV circulation. Every year, there is a final stratospheric warming event, as we proceed into spring, as the Sun starts warming up the polar region. There are signs of warming waves entering the upper stratosphere. As we head deeper into march, as the sun angle gets higher over the arctic, the PV will come under more and more pressure from these warming waves. As some point it will weaken, and most likely basically collapse.  The models are supporting this idea. So, in my opinion what we’re seeing is going to be the last stratospheric warming event until next fall/winter.  Right now, it looks like we will see two warming waves. In the image below we can see one wave over the North Pacific and a stronger one around the Atlantic. The PV should become very elongated. The models, see this happening as well. Looking at the GFS, we see the PV does become elongated. This should result in the PV splitting with  one side going over Eurasia the other over North American and or Europe.

We are currently seeing changes in the pattern over Alaska and back into Eurasia. I expect to see this evolve farther as we get deeper into March and April. The Pacific ridge that looks to build into the western CONUS, should lead to a trough over the eastern CONUS.  With this idea, we should see the pattern cool down as we get into the end of March and for at least the first half of April.  But with the warm northern Atlantic and Gulf of Mexico, those warmer Sea Surface Temperature (SST) should help bump up our nighttime lows.

The Verdict:

March

I expect above average overall temperatures for March here in the Northeast and Mid-Atlantic region.

April

April very will could be the coolest month of Spring 2020. Overall temperatures should end up average to slightly below average.

May

I expect to see overall temperatures average to above average during the first half, then ending the month well above average

Looking at Spring as a whole

March through May should end up overall above average temperatures for New England, New York State, and the eastern Mid Atlantic Region. While Southwest into southern Pennsylvania and western Maryland will see overall temperatures well above average. This Spring also looks to be overall wet. We will see dry times…but the overall active pattern should ensure overall rainfall to end up above average for the Northeast and Middle Atlantic region.

Spring 2020 most likely will see an active severe season. The Pattern that looks to setup will support a lot of severe activity. The Polar Vortex will break down at some point, allowing the cold air that has been bottled up, to drift south. The Gulf is very warm. The resulting clash of air masses, will allow for plenty of chances for severe weather outbreaks. 

Quick look at Summer 2020.

Summer could see temperatures well above average.

I will be releasing my 2020 hurricane outlook in a couple of weeks.

I hope you enjoyed reading my thoughts.