Showing posts with label el nino. Show all posts
Showing posts with label el nino. Show all posts

Thursday, April 28, 2016

The BIG Winter Recap - Part II - Northern Ohio (Summer Thoughts)

The last "cold" morning in Ashtabula this winter
The strongest El Nino since 1997-98 and a stable arctic tempered the cold of the last two winters. Temperatures across northern Ohio were well above normal with below normal snowfall similar to the winters of 2011-12, 2001-02, 1997-98 and 1982-83. Two of those three were strong El Nino winters.  Our outlook last fall was for above normal temperatures and slightly below normal snowfall.




Above normal temperatures were more extensive across the US. According to the NCDC, global ocean temperatures were at record levels.  (See PART I of my winter recap for other drivers)



Given the panhandle storm track forecast back in September/October, we were very confident that we would get hit with at least ONE big general snowfall which would boost snow totals into the 50-55 inch range. Overall, the heavy snowfalls stayed south and east of northern Ohio which kept our totals even lower. Those big snows came VERY close to northern Ohio!

BIG SNOW ACROSS SOUTHERN OHIO...VERY CLOSE TO CLEVELAND & AKRON

How does this winter compare to the last two cold winters? How does this compare to the similar winter of 2011-12?  Here are the final tallies.  The same metrics used in last winter's winter recap were used this year to keep everything consistent.












Everyone thought winter was over until our early April snowfall. The April snowfall was almost 24% of the entire winter total; second highest ever!




 Lake Erie Ice Cover reached a peak of 75% for a few days in mid February.


 That's a bit misleading as the peak ice cover went from 3% to 79% in 3 days! In 11 days, it dropped to ZERO in a week and a half.  GRAPH BELOW

Ice cover was thicker and more widespread for much longer last winter.  For comparison, last year it took 28 days to reach 94% and it stayed above 90% for 47 days. Whereas in the winter of 2011-12 (similar to this winter--see above), ice cover reached 13%, only 6 days above 10%.  


Ice cover during the last big El Nino back in 1997-98 was even LOWER than this year. A whopping 8.4% maximum!






Will the leftover winter El Nino play a role in our summer temperatures and precipitation?  Will El Nino continue to weaken?  If so, how will this effect the summer and upcoming autumn? Will severe weather occur more frequently?  Summer Outlook coming up in a few days!  Check out fox8.com 






Wednesday, December 23, 2015

Let's Clear Up A Few Things...

Many wonder why I write so much about the psychology of weather. If you read the comments on most of my posts over the last several weeks you'll see why: They believe what they want to believe. They use social media as a conduit to say whatever impulsive thought they want without recourse. Perception is the ultimate reality.

I use social media and my blog to show why weather events occur the way they do. I post stats and records about past weather to show some perspective in the hope that this will help viewers of our station and the general reader. Often times it just doesn't work...much to my dismay.

So let's clear up a few things. Rather than use science to explain the why we do what we do, I'm using straight forward bullet points. Let's wipe the slate clean and start out fresh and new as we approach the end of the year.

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1) It WILL snow at some point. It always does. And no, I don't like snow.

2) The warm weather is playing with our minds.  Our weather perceptions (cognitive biases if you will) are very strong.  We are not immune.  We are all human.  Recognition of these preconceived notions is the first step in an objective understanding the weather and the science that governs it.

2a)  We hate forecast uncertainty. Here's why LINK

3) Contrary to what you might believe, weather forecasts are more accurate than they were 15 years ago.  According to this study, "the accuracy of the 8-10 day forecast today are similar to a 5-7 day forecast 15 years ago. Hurricane accuracy is greatly improved since Hurricane Katrina LINK.

4) Our morning show here at FOX 8 is on for 6 hours. The weather forecast between 4 and 10am can change as the conditions change. Forecasts are not frozen in time during each newscast.  The weather doesn't stop for television.

5) The decision to break into a popular TV show or sporting event with a weather update is NOT an impulsive one. Stations have different philosophies on when to break into programming. I can't speak for the others. However, my station WJW-FOX 8 only breaks during a tornado warning or a significant winter weather event (widespread, blizzard-like snow). If you send a comment complaining about our stringent guidelines, you obviously care more about football than being warned when a tornado warning is issued.

6) Contrary to many weather maps on the air, the atmosphere is three dimensional and ever changing. Imagine the atmosphere (especially during sleet, freezing rain events) like layers of a wedding cake.  Each layer of icing represents the different layers of air at different temperatures with different types of precipitation.

Note: The wedding cake analogy is mine and mine alone. I invented it.

7) Moon or sun halos are not uncommon. They are beautiful sights caused by the bending, splitting and reflecting of sunlight through ice crystal clouds.  We have hundreds of photos.

8) I'm not a fan of phone weather apps that promise super-local weather forecasts for your backyard. They are like unicorns.  They don't exist.  Most are computer generated data approximated based on your location via GPS.  I trust a human generated forecast (via NWS or your local tv station) every day of the week.

9) Jet contrails are not chem-trails.  They, like, unicorns don't exist.  I don't like conspiracy theories.

10) I have no control of weather, news or school closing promos that run 15 times per hour. The promotions department is on the first floor.

11) These above normal December temperatures were mentioned in a blog post on my weather blog in early September and again in our FOX 8 winter weather outlook. Yes, pre-Christmas warmth has happened before.  Remember 1982?


12) Simply because the weather has been warm or cold, wet or dry doesn't confirm or deny climate change in any form. I'm an operational meteorologist who happens to be on television.  Keep your subjectivity or bias to yourself.  So please don't send me anecdotal evidence confirming your preconceived notions.  See number 2 above for the reasons why.

13) We forget that last December was above normal with no snow for only the 3rd time in 140 years.  Christmas week in 2014 was the 8th warmest on record in northern Ohio.

14) This warmth is driven by BOTH El Nino and a strong Polar Vortex not just El Nino. Remember the Polar Vortex from last winter?  Yes, it's real (LINK)

15) Storm systems like what we are seeing currently which develop over Texas and move northeast--termed "Panhandle Hooks"--are more common in El Ninos.  Wet snows are more common from Texas through the mid-Atlantic in these years.

16) Contrary to what we believe, you cannot use one or two days or a weeks worth of weather as a predictor or the season ahead. In other words, a warm or cold December is not an indicator of the spring or summer ahead. The drivers of winter aren't necessarily the drivers of spring and summer.  It's not an apples to apples comparison.  (Remember December 2014 was warmer than normal.  Then the bottom fell out: January through February was the 6th coldest on record, coldest since 1978)

17) The fact that I have said over the last week that colder air in January will replace the relative warmth in December doesn't mean the entire winter will be colder than average. (see FOX 8 outlook issued in October)

18) Lake Erie water temperature is 45 degrees. It's been this warm before on the 22nd of December: 2001 and 1998 for starters.  The water temperature is taken at a depth of 30 feet. No one seems to have an answer as to why.

19) There is a TON of science behind seasonal outlooks. The Farmers' Almanac is not science (although I enjoy reading it).  Weather consulting companies issue seasonal outlooks tailored for their clients. This sector has grown significantly in recent years.

20) Many readers will ignore everything I typed here and replace it with their own conclusions regardless of their validity.

I reserve the right to add to this list.

I hope this helps.



Wednesday, December 09, 2015

Warmth Continues...When Will It Flip To Winter?

No one is complaining about the above normal temperatures after the two past harsh winters. Above normal temperatures across the eastern 1/2 of the US.  This warmth is not unexpected given the strong El Nino reaching peak strength though I am somewhat surprised that the warmth has been this consistent.



It can't last forever.  So when will it flip or at least trend colder with higher chances of snow!

Remember our preliminary December outlook issued back in early September showed the core of the high pressure/warmth across the northern states into Canada with the core of the low pressure centers across the south (panhandle low type systems).
Through the first week or so, the core of each HIGH and LOW is much stronger than anticipated yet they are roughly in the same position as our forecast 3 months ago indicated. However, the southern lows (Panhandle type) are far weaker and, as of this writing--December 8th--are just now showing signs of developing. (see the smaller "Ls").
Since November, the warmth has been extensive with below normal temperatures in the west. Warmer colors indicate above normal temperatures, cooler colors below normal temperatures.



Some computer model projections have been bullish in tracking these southern lows further east and the warm ridge further north into Canada by the beginning of Christmas week.




The big questions for the end of the month and Christmas week: 1) How fast will the ridge lift north and 2) how strong will the low in the southwest/panhandle region push east?

We do know this: Any easterly migration of the southwest low along the southern jet stream will increase our chances of a wet panhandle-type snow by month's end. 


The chances we will receive wet snow from a panhandle low will climb further after the first of the year. 





Tuesday, November 24, 2015

How Much El Nino Warm Water Is Out There?

Often times, weather maps are hard to conceptualize unless you use them everyday. Since the summer, my El Nino posts have been filled with colorful maps analyzing ocean water temperatures, air pressure, possible winter storm tracks and air temperature. These maps are pretty basic for meteorologists and atmospheric scientists who view these everyday. For the non-scientific viewer, the colors can be as convoluted as a Rorschach diagram if not properly put into perspective.

Below is a picture of the Pacific Ocean temperatures relative to average.  Warmer and cooler pockets are easily visible. The El Nino is the band of warmer colors in the middle along the equator.

Just how large is this area of warmth?  How much water are we talking about?

Consider that the length of Lake Erie is approximately 240 miles. The distance across the main ENSO region in the yellow box below where the core of the warmth is located is roughly 5000 miles. The depth of this warmth is roughly 100 meters or slightly more than 300 feet.


The area boxed in yellow is roughly equivalent to 75% of the contiguous United States.

Performing a quick volume calculation (area times depth), we come up a HUGE volume of relative warm water in the El Nino region using these parameters: 




The VOLUME water in the equatorial Pacific Ocean where water temps are running at least 3 degrees Celsius (~5 deg Fahrenheit) above normal is more than 25 TIMES GREATER than volume of ALL the Great Lakes! WOW!



Tuesday, October 27, 2015

El Nino Update: 1997 vs 2015

I plotted the weekly sea surface temperature anomalies starting in early June for the ENSO 1.2 region (closest to the South American coastline).


 Notice how 2015 is running cooler versus the 1997 event. Another component into our winter weather outlook which airs this Thursday at 6PM on FOX8!


Friday, October 16, 2015

Precipitation and El Ninos: West Coast Rains Not Always A Lock


Not all El Ninos are alike. We've heard this time and time again. Sea surface temperatures are never exactly alike. Jet stream position varies. Overall winter temperatures vary too as does the location of above and below normal precipitation. We remember the El Nino of 1997-98 that produced heavy rains out west.  But that's not always the case.

We examine the top El Ninos according to the ONI Index from this site. We only examined the El Ninos that are ranked MODERATE, STRONG AND VERY STRONG.

THE STRONGEST EL NINOS (1997-98 and 1982-83)  

Storm track kept heaviest precipitation along the west coast and in the southeast.  At or below normal precipitation around the Great Lakes.



STRONG EL NINOS - RANK #3, #4 AND #5

Storm track is still strong in the deep south with a southerly shift out over the Gulf of Mexico with above normal precipitation.  Aside from the winter of 1957-58, precipitation along the west coast is less in these years. Still below normal precipitation across much of the Great Lakes.




MODERATE EL NINOS

Southern storm track is still strong but weaker during the winters of 1986-87 and 1963-64. Storm track shifted much further north into the Ohio Valley and Mid-Atlantic during the winters of 2002-03 and 2009-10 with heavy wet snows. During many of these winter, well below normal precipitation was observed along the west coast especially during the winter of 1963-64






Contrary to what you hear, its not a guarantee that El Ninos always produce heavy precipitation events across the west coast and the Pacific Northwest. It does appear that the chances are greater with stronger El Ninos per the ONI Index.  The southern storm track seems to be more consistent--with varying intensities--in each of top El Ninos. 

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A few side notes:

* Another modulator of the El Nino and storm track is the mode of the PDO (Pacific Multidecadal Oscillation). The winters of 1957-58, 86-87, 87-88, 97-98, 2002-03 and this year so far all have PDO values strongly positive.

* Yet another area of the Pacific that may have ties to the evolution of El Nino is the Pacific Meridional Mode located between the equator and Baja California. The link between the two is being studied. Here is a paper published in 2014.  Looking at the data from late summer through fall during early El Ninos, late 1957, 1986, 2009, 2015 (and partly 1982 although it was trending cooler) all had positive values (above normal water temperatures).

Do we see some matches above for this winter?  Hmmmm.







Monday, September 07, 2015

The Upcoming Winter Weather (2015-16) MIGHT Look like This

North Country Public Radio


I'm thinking out loud today so bare with me.

Over the last few days, I was playing around with the constructed analogs of similar winter years. Using a set of 6 best fit years and weighting them equally, I constructed a blend for each month starting in November and ending with February showing the upper level pattern across the North American Continent. The color colors show where the storm system would develop (Low pressure). The warmer colors show where High Pressure systems reside.

The first burst of colder air occurs in November, the pattern relaxes in December then reloads after the first of the year. Can you see how the southern jet stream becomes very active, dominant force in the second half of the winter. February shows the much higher frequency and strength of low pressure systems from the southwest. This indicates a higher propensity for wetter snows from northern Texas, northeast into the Mid Atlantic states and Ohio Valley similar to 2010.


UPPER AIR PRESSURE (500 mB)
NOVEMBER BLEND
DECEMBER BLEND
JANUARY BLEND

FEBRUARY BLEND
SURFACE TEMPERATURES


Last winter's actual temperatures versus our Winter Outlook issued in October.  Not bad.

The overall temperatures for this winter according to the best matches are not as cold across the eastern 2/3rds of the US when compared to the winters of 2014-15 (recap of last winter at this link) or 2013-14.
NOVEMBER BLEND
DECEMBER BLEND
JANUARY BLEND

FEBRUARY BLEND
Snowfall departures (above or below average) are much higher in January and February during moderate to strong El Ninos especially when these El Ninos are more central based (Modoki, using the EMI Index). 

Will this strong El Nino have some central based signature tendencies? Maybe more eastern El Nino characteristics thus a warmer winter overall with little snow? 

The Constructive Analog from Huug van den Dool's page on the CPC site shows the core of the ENSO warmth in the ENSO 3.4 region with a slow drift WEST toward the Dateline by late winter.

Will this verify?  Only time will tell. 


Many meteorologists in the private sector don't like using the Analog Method too literally because the probability of finding an exact match over such a large area is incredibly small. I get that. However, I have found that analogs give a glimpse into how the atmosphere responds to the various drivers in closely matched years. This group of "best fits" for this winter has stayed consistent over the last several months.  Several notes: Analogs are only one of several tools that I use in assessing seasonal outlooks. El Nino is only one of the many factors that will play a role in our winter weather. I did not include any ENSO dynamic model guidance in this post. That is a story for another time.