October 31, 2014

El Nino winding down and maybe a little La Nina?

Even though predicting weather a mere 24 hours in advance can be very difficult, every month the kind folks at the National Weather Service’s Climate Prediction Center take on the challenge of long term forecasting. While most of us have little practice use for this report, they can be encouraging for those of us still stuck in the dead of winter. I’m definitely getting tired of scraping Wisconsin ice and snow off of my car, so I’m happy to hear that the 3 month outlook forecast calls for warmer temperatures in the western third of country with a pocket of warmer climate that stretches along the northern border states to the Mississippi River Valley. Predictions for the rest of the country are up in the air.

The precipitation forecast calls for below average rainfall in the western and central Gulf Coast Regions along with the Far Southwest. Above average rainfall is predicted for the southern Rocky Mountains and the high plains state. It’s a toss up for the rest of the country.

Can’t forgot about Hawaii – long-term prediction: big surprise….paradise (If you must know, they are predicting average temperature with below average rainfall amounts).

How do they predict the long-term weather?
There are many factors that go into these predictions. An interesting factor is the so-called “memory” effect that ice and snow cover has on climate. For example, if there is a lot of snow on the sun doesn’t heat the ground very well because the energy from the sun is reflected by the snow so the climate “remembers” the recent colder weather. One of the most influential factors is the temperatures of the Atlantic and Pacific Ocean. While El Nino is the most powerful and well-known trend, there are other ocean trends like the Northern Atlantic Oscillation.

Speaking of El Nino, the current El Nino event is winding down and the Pacific Ocean will be ENSO-neutral (El Nino – Southern Oscillation is the full name of the ocean temperature pattern) sometime in the next month or two. In fact, by the summer we may be heading towards La Nina conditions but it’s way too soon to know for sure.

What are El Nino and La Nina?
El Nino and La Nina refers to changes in the average temperatures in the Pacific Ocean that have impacts on weather worldwide. An average increase of 0.5 degrees C in the central topical Pacific is the official definition of El Nino and a decrease of 0.5 degrees C is the definition of La Nina. This doesn’t seem like much, but .5 degrees C of warmer water multiplied by a huge area of ocean is a lot of energy and has a very noticeable effect on global weather.

If you are interested in learning the effects of El Nino on the weather in your location, check out this good website from the National Oceanic and Atomospheric Administartion (NOAA) Here’s a website discussing La Nina effects.

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Posted by Tim Roth, author of the political blog Think Anew and Act Anew

Sources:
1. “Long-Lead Seasonal Outlook – February 15th 2007″, Climate Prediction Center, National Weather Service.

2. “El Nino-Southern Oscillation”, Wikipedia entry

2006 Hurricane Season

Much to the relief of the Gulf Coast (especially those still rebuilding after Hurricanes Katrina and Rita), hurricanes didn’t really make the news in 2006. As the hurricane season 2006 begin last June, it was predicted there would be 13 to 16 named storms, 8-10 hurricanes, and 4-6 major storms.

Thankfully, not a single hurricane hit U.S. shores. Why was the forecast off?

El Nino…. (seems like everything weather-related can be blamed on abnormal warm waters in the central Pacific Ocean). The El Nino effect increases westerly winds and steers hurricanes away from the East Coast where they eventually die out in the cooler waters of the Northern Atlantic.

What is interesting about 2006-2007 El Nino event is that it was unexpected and had a rapid effect on weather worldwide. In fact, it was so rapid that it caught the highly-skilled hurricane forecasters off guard.

The residents of New Orleans definitely appreciated El Nino this year, but meteorologists warn that we are still in a very active hurricane period. Furthermore, the planet has been experiencing some of the warmest years on record. This means that the Gulf of Mexico will be a very warm body of water and a ripe area for hurricanes to gain incredible strength.

Stay tuned for more on hurricanes, especially as the 2007 hurricane forecasts are released.

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Posted by Tim Roth, author of the political blog Think Anew and Act Anew

Source:
“2006 hurrican season bows out quietly”, CNN.com article

Happy Groundhog Day

At 7:28a this morning, this is what Phil the Groundhog had to say from his burrow at Gobbler’s Knob in Punxsutawney, Pennsylvania: [1]

El Nino has caused high winds, heavy snow, ice and freezing temperatures in the west.
Here in the East with much mild winter weather we have been blessed.

Global warming has caused a great debate.
This mild winter makes it seem just great.

On this Groundhog Day we think of one thing.
Will we have winter or will we have spring?

On Gobbler’s Knob I see no shadow today.
I predict that early spring is on the way.

Thanks Phil! That’s wonderful news given that tomorrow’s low temperature is going be to -11 degrees F (-24 C) here in my neck of woods in Wisconsin.

With his knowledge of global warming and El Nino, Phil is obviously smarter than the average groundhog (decent poet as well) but what do other meteorologists have to say about winter in the United States?

As Phil mentioned, El Nino has been affecting weather worldwide. Temperature readings in the Pacific Ocean have slightly decreased from above average levels which means El Nino is weakening but a warmer ocean will have some impact on the climate.

Here are the highlights from the February-March-April outlook report from the NOAA Climate Prediction Center:

Temperature: [2]
1. Good chance for warmer than normal temperatures for the northern two-third of the country including Alaska
2. Normal temperatures for Southeastern United States from Texas to the South Atlantic Coast
3. Equal chances for above, below, normal temperatures elsewhere

Precipitation: [2]
1. Below average for Northern Rocky Mountains, Ohio & Tennessee River Valleys, and Western Great Lakes region.
2. Above average for southern third due to El Nino. To be more specific, Southern California, Southwest states, Texas, Southern Plains states, Gulf Coast, Florida, coastal plains of Georgia and Carolinas.
3. Equal chances for above, below, normal precipitation levels elsewhere

Predictions for Hawaii: [3]
Big surprise for you….tropical paradise every single day! :) Actually, long-term forecasts predict below average temperature and precipitation for the next three months.

So, Phil and the National Weather basically agree.

Happy Groundhog Day!

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Posted by Tim Roth, author of the political blog Think Anew and Act Anew

Sources:
1. Phil’s 2007 Prediction
2. February-March-April outlook report for Continental US and Alaska
3. February-March-April Outlook for Hawaii