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 1st, with Astronomical spring beginning on
Thursday March 19th, 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.
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.
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.
I find this very inspiring. Having no background in weather forecasting, this predictions give me incentive to study the subject more. Even if a prediction is wrong, it is an opportunity for more reflection on the prediction variables.
ReplyDeleteThanks for taking all this time to present this!
You're welcome........and thank you!
ReplyDelete