Friday, April 7, 2017

My April, 2017 Atlantic Hurricane Outlook.


Back on March 26th I posted my thoughts on how the hurricane season looked to unfold.  Looking at everything, I really haven't changed my mind. As far as I can see, I was the first or just about the first to post numbers on the 2017 hurricane season. I wanted to post before the Annual National Tropical Weather Conference was held this year.  I also wanted to beat Colorado State University's April outlook. Why? Because I wanted to make it clear that my ideas are sound, and lay the groundwork , by getting my predictions out there first.

The Atlantic hurricane season runs from June 1st until November 30th. But that doesn't mean tropical cyclones can't form before or after those dates.

Back in March, I said my analog years were, 1951,1953,,1957,1972,1997,2015. Since then I looked at and added 1965, 1976, and 2002. All of these years had some similarities to 2017.


Teleconnections:

The North Atlantic Osculation as primarily been positive since January.  So the North Atlantic Sea Surface Temperature (SST) anomalies have been cold. The cooling off of the SST increased in March.  So now we have cool SST in the North Atlantic, cool tropical SST off the West Coast of Africa, with warm SST off the East Coast of the United States. This places the Atlantic Multidecadal Oscillation (AMO) in a basically negative phase.

The  El Nino-Southern Oscillation (ENSO) is currently neutral. I've been posting on My Facebook weather pages, and I also talked about it in my March 26th blog post. So I won't go into a lot of detail on that. But, the ENSO looks to head for El Nino conditions. During the 2016 hurricane season we were experiencing a strong El Nino. Then late in the fall we transitioned into La Nina. During winter 2016-2017 the La Nina stayed very weak. This is one of many reasons why the winter turned out the way it did.

This year I don't think we will see the return of a strong El Nino. Instead I think it will be weak to moderate.  I don't think we will see a El Nino until at least mid-summer. Right now, the atmosphere is still acting like we have a weak La Nina; it will take awhile for the atmosphere to catch up. So, there wouldn't be Atlantic influence until we get into the hurricane season. 

Predictions from other major weather outlets.

Colorado State University (CSU):

They issued there outlook on the 6th of April, 2017. The team from CSU said they expect 11 named storms, 4 hurricanes, 2 of them major Cat3 or higher.

Accuweather:

 Issued their hurricane forecast April 5th, 2017. They say 10 named storms will form, 5 will become hurricanes, 3 will become major.

Tropical Storm Risk, INC (TSR):

TSR a prestigious private hurricane forecasting company in Britain, issued their hurricane outlook on April 5th, 2017.  They say they expect, 12 named storms, 6 hurricanes, 2 of them major.  

Weatherbell:

They released their thoughts on numbers for the 2017 season, on 31 March, 2017. They have listed, 10-12 named storms, 4-6 hurricanes, 1-2 of them major.

The numbers I released on the 26th of March, 2017:

I said, my early thoughts were, 10-12 named storms, 3-4 hurricanes, with 1 major.

Last season's tropical cyclone numbers:

In 2016, there were 15 named storms, 7 of them became hurricanes, with 4 major hurricanes.


The bottom line:

The combination of a positive AMO and El Nino will increased trades winds over the Main Development Zone (MDZ) of the tropical Atlantic.  We also have those cool SSTs, in the eastern Atlantic.  All of this will severely curtail tropical development in the MDZ.  So the odds of Cape Verde tropical storms will be much lower than average.  This same thing happened in 2016.

Those warm SSTs off the East Coast of the U.S., and the warm waters in the Gulf of Mexico and Caribbean will set the stage, for tropical cyclone development in the western Atlantic Basin.  As was the case last year, most of the tropical development should develop closer to the U.S. main land.  The warm SSTs also, increased the odds of stronger hurricanes coming up the East Coast.

My Call based on right now, is 10-12 named storms, 4-5 hurricanes, with 1-2 of them major.
 

If I have to adjust anything, I will release an updated outlook, during the last half of May.
 
 

Thursday, April 6, 2017

Summer 2017 Outlook


Despite busting  my winter 2016-2017 temperature outlook, my snowfall outlook got it right for the most part. Which shows, you can get a lot of snow, even during a warm winter.  Summer outlooks are much harder to forecast,  than winter outlooks. For this reason this outlook is a little more limited in scope than my typical winter outlooks.
 

We have a developing El Nino in the Pacific. It won't be as strong as last summer's.  I do think it will act like the La Nina over the winter.  The 2017 El Nino will be short lived. It should be weakening as we head into the upcoming winter.  There is a good chance this will end up being a El Nino Modoki event. If this is the case late fall and the winter will see the greatest impacts in the Mid Atlantic and Northeast.






 

Looking at the sea level pressures in the Pacific, the SOI is looking to be negative over the next 6 weeks, This trend looks to continue into Summer 2017.  Those cold SSTs in the Indian Ocean and around Indonesia means this won't be a long lasting El Nino. The upcoming El Nino should end up being weak to moderate.
 

My analogs  were difficult to compare to this year. But the closest I could find were: 1959, 1960,1961, 1980, 1983, 2002, 2006, 2009. None of these were a exact match. But they were close enough to gather some insight.   (Note: NOAA has been readjusting the old data. This makes past events look cooler than they might have been. ) So that doesn't help.






 

Temperatures:

The summer will start off warm. But then we will cool off after midsummer.  Typically transitions from La Nina to El Nino lead to overall cooler summer, especially during the 2nd half of summer.  This is because the atmosphere takes a little time to move from one phase to the other.  Overall, this upcoming summer, looks to be average to very slightly above average in temperatures.  Part of the reason will be those very warm sea surface temperatures off the East Coast.

 


Precipitation:

On my Facebook weather pages, I've been talking about how I expect to see a active severe season in the Northeast.  Also the threat that I see from close to the East Coast forming tropical cyclones, again those warm SSTs off the East Coast, has to be taken into account.
 
We have an ongoing drought going on in New England down into eastern Pennsylvania , New Jersey, and the Mid Atlantic. This is especially true for Connecticut and Long Island; the rest of the region is doing OK.  There is also drought in the Southern U.S. I do expect to see the active pattern we're in erode quite a bit of this over the next couple of weeks. But these areas will have to be watched. As, they would have a part to play on where the heat sets up.

I don't anticipate this to be a typical dry El Nino.      

 


Severe:

The severe season  in the Northeast runs from June through August. The Plains will be cooler than average June July and August. This is typical for El Nino years.  With a trough setting up in the Plains. We would see slight ridging over the east coast, with an active storm track looking to be in the cards. Severe weather in the Northeast will ramp up. This should end up a fairly active year for severe weather, with perhaps several severe outbreaks over the region.

 

Bottom Line:

This Summer is going to see temperatures warmer temperatures in June into July .  Then we will start to see a change to cooler overall temperatures mid to end of July and August.  I expect the temperatures to end up over all average to slightly above average for New England and New York State into Western Pennsylvania. With temperatures  over the rest of Pennsylvania and the Mid Atlantic to be moderately above average.  But we won't have the sweltering heat we had in Summer 2016.
This Summer will see a wet June and July, with things starting to dry up a little in August.  Overall I think precipitation will be average to slightly above average.  The wild card will be severe season and tropical activity. But if these play out like I think this Summer and Fall could be wet.
 
I will have a separate post on the 2017 Atlantic Hurricane Season, and my thoughts on the Severe Weather Outlook for June through August.