How much snow? 22nd annual long-term winter forecast of hurricane

Let's get right to the point. We are in a cold and snowy winter. But how much snow? And at what temperature do the temperatures go? I measure several important factors to reach this conclusion.

It all started in 1997 with a glimpse of something I had only seen twice before. A vast area of ​​the tropical Pacific, larger than the United States, was MUCH warmer than normal. They called it an El Niño. I had just read a study showing the possible link between an El Niño fort and warm, wet, snowless winters in the eastern United States.

So, I went up in the air and predicted an exceptionally warm winter with very little snow. We had a record winter and our TOTAL snow was less than an inch. This attracted attention. Now, a winter forecast is expected each year in November.

The winter forecasts are as simple as those of 1997. We can always count on Major El Nino to offer us warm winters with little snow. But most years are not like that.

"THIS IS JUST LIKE …"

We have learned that there are many more factors in the ocean and the atmosphere that can help us with seasonal forecasts. We also know that there are no two identical winters. There is always a part of the ocean that is different. There is no perfect badogue year. But some have a lot of similarities.

Whether we have an El Nino or the opposite, La Nina, often makes a big difference. But it is not so clear when it is weak or moderate (like most years).

FACTORS

1. EL NINO

It is no longer just El Nino against La Nina. Where El Nino is the most concentrated, it is also important. Most El Nino cover a large part of the tropical Pacific. Less frequently, the central tropical Pacific has the most concentrated heat. It's called a "Modoki".

Although many El Ninos lead to warmer winters, those in Modoki Nino tend to be colder and snowier, especially if it is low or moderate.

This winter: MODOKI El Nino weak to moderate …

FAVORS MORE COLD AND MORE SNOW THAN NORMAL

2. "BLOB" OF THE NORTH PACIFIC

We have seen it several times this decade. A wide path area above normal ocean temperatures in the North Pacific. This results in an increase in HALT pressure around Alaska and northwestern Canada, forcing the Arctic air into the eastern United States.

The red colors at the top, just in Alaska and in western Canada, represent the current 'Blob'. This is an important factor in what our winter will look like.

This winter ENCOURAGES MORE ARCTIC INVASIONS

3. EURASIAN SNOW IN OCTOBER

It is rather an indirect effect, but a rapid advance of the snow in mid-October around the world is linked to winter cold and snow in the eastern United States.

This year, snow cover in Eurasia started very slowly, but progressed rapidly towards the end of the month. My research shows that this combination is the most favorable for snow in winter.

So this winter FAVORS MORE SNOW

4. THE QBO

The "quasi-biennial oscillation" occurs very high in the stratosphere and tends to change direction every two or three years. During transition periods, blocking patterns in the upper atmosphere occur more often. Blocking patterns, especially the El Niño years, favor the Nor'esters (and the stronger ones) more. If it's cold enough, it means snow.

The QBO index tends to have a stable trend and tends toward the transition period.

This winter FAVORS MORE SNOW

5. SOLAR ACTIVITY

Meteorologists are a bit controversial, but there seems to be a correlation between particularly low solar activity on the sun and colder, snow-covered winters in the United States.

The graph below shows the clear cycle of sunspots in recent decades. Some of our most cruel winters have occurred down the cycle, while there is virtually no sunspots. We are close to the bottom this year.

This winter FAVORS MORE COLD AND SNOW

6. The AO & NAO

What is happening in the Arctic and the North Atlantic can be just as important as the Pacific. But things like the Arctic Oscillation and the North Atlantic Oscillation are almost impossible to predict months in advance (unlike El Nino, QBO and The Blob). So, they are still considered a "joker"

A negative AO means unusually high pressure at high levels on the Arctic. This forces the coldest air from the south to Canada and the United States and forces the flow of polar jets to move further south than normal. The record winter of 2013-2014 was characterized by several giant snowstorms with a strongly negative AO.

When the NAO is negative, the HIGH pressure is centered near Greenland. This pattern favors slow-moving coastal storms in the eastern United States. A negative NAO is often one of the ingredients of our biggest snow storms in Nor'easter.

The Eurasia snow connection mentioned above can be connected to -AO. So maybe that can be predicted.

7. FUSION OF ARCTIC ICE AND CLIMATE CHANGE

It has become increasingly clear to many forecasters and climatologists that mbadive melting of Arctic ice is affecting weather conditions. One of the impacts lies in more blocking schemes, notably -AO and -NAO.

It is probably not by chance that 3 of the 4 biggest snowstorms in Philadelphia have occurred in the last decade (2009, 2010 and 2016). The combination of more blockage and more water vapor due to global warming is a recipe for big snow storms – IF it's cold enough. And an -AO can help with that. These recent changes must be taken into account during the seasonal forecast.

8. FORECAST OF SEASONAL COMPUTER MODELS

Until recently, predictions of specific computer models were not considered useful by most forecasters. But as our knowledge of the atmosphere and models improve, so are the forecasts. Now, I really want them to show (of course, the US model, the GFS is the least reliable in this area). The European and UKMET models have recently predicted models that favor cold and snow for us. The same goes for the Canadian and Japanese models. It's a lot of agreement.

This winter FAVORS MORE COLD AND SNOW

FORECAST (FINALLY!)

So, you see, practically ALL the important factors that I consider to be geared towards more cold and snow this winter. The only questions I have are: "How cold and snow should I go?

The answer is to examine previous years with similar conditions to those called badogues. Analogues this year show a dramatic trend, especially for February.

The first map shows an average altitude of about 20,000 feet in the atmosphere in February – a key level for forecasters. The lower pressures in the northeastern United States are extreme for a map like this. And the very strong pressures on Greenland suggest a strong -NAO. This combination SCREAMS East Coast Snowstorms!

And the map above illustrating February temperatures follows the pattern at altitude: an unusual cold in the eastern United States

Based on the above reasoning and looking at the badog years …

First, some highlights

* colder than "normal" winter

* more snow-covered than normal winter

* the coldest compared to normal: February

* the snowiest: February (by far)

* 2 major snowstorms in February

* December cold with snow above normal

The specificities-for Philadelphia

SNOW TIME

DEC. 7 "-2.0 degrees

JAN 8 "+1.0

February 16-3.0

MAR 4 "-1.0

TOTAL 30-40 "(" Normal "is 22.4")

For other cities in our region, here are my estimated seasonal snow forecasts:

Allentown 50 "

Downingtown 45 "

Wilmington 32 "

Atlantic City 28 "

Millville 26 "

Poconos 85 "

Believe it or not, it is possible that I am too conservative with this forecast: not enough snow or cold. But the models that seem clear now could change in the months to come. In any case, this winter deserves to be watched. Some will like it, others will hate it.