Tuesday, December 27, 2011

Northeastern Ohio's First Widespread Snow

As of 8AM Tuesday morning, the rain has spread throughout most of northern Ohio. Some reports of sleet/snow near Vermilion and Lorain.  Temperatures are still not super-cold although they are slowly falling out west.  This marks the last southern/panhandle storm system for a while. The transition to a more progressive/clipper-like pattern this week and into the first week of 2012.


When will the rain/sleet transition over to ALL snow?  Here is the map for noon today and then 6PM today.


ALL of northeastern Ohio will seen 1-3" of snow by sundown.  Additional accumulations with the following lake effect overnight tonight brings the amounts to this...


Monday, December 26, 2011

Is Winter Finally Coming? Our Changing Pattern in January

THE PATTERN IS BEGINNING TO SHIFT BACK TO A CLASSIC WINTER ONE.  IN FACT, LOOKING AT THE MOST RECENT PROJECTIONS FOR NEXT WEEK AND BEYOND, THE FLOW IS SETTING UP TO BE EXACTLY HOW I THOUGHT THE WINTER WOULD START BACK IN LATE NOVEMBER. 




THE COMPUTER PROJECTIONS WERE HAVING A HARD TIME LOCKING INTO THE NOVEMBER/DECEMBER PATTERN BECAUSE THE FLOW WASN'T A TYPICAL EARLY WINTER ONE. 


IT REACTED AS IF IT WAS AND PRODUCED RESULTS THAT SHOWED THE COLD AIR TO BE WAY TO STRONG.  NOW, THE COMPUTER PROJECTIONS ARE COMING INTO BETTER ALIGNMENT. EITHER THEY ARE PICKING UP ON THE CHANGING CONDITIONS IN THE SHORT-TERM OR THEY ARE ARE PICKING UP ON THE SHIFTS IN THE GLOBAL, LONG WAVE, LONG TERM PATTERN.  I THINK THE LATTER OF THE TWO BEHAVIORS FITS BEST. LET ME SHOW YOU WHAT I MEAN.

TODAY CURRENT MAP SHOWS THIS "CUT-OFF" LOW COMPLETELY SEPARATE FROM THE MAIN FLOW OF AIR TO THE NORTH.  THIS "CUT-OFF" HAS SAT OVER THE SW FOR WEEKS WITHOUT MUCH MOVEMENT.  THE PROJECTIONS HAVEN'T HANDLED THIS FEATURE VERY WELL.  OFTEN TIMES, IT'LL MOVE THE LOW SLIGHTLY MORE WEST BY SHOWING BURSTS OF COLD AIR OVER NORTHERN OHIO WHICH NEVER HAPPEN.  


NOW FAST-FORWARD AHEAD TO RIGHT AFTER THE FIRST OF THE YEAR.  THE LONG TERM PROJECTIONS SHOW THE "CUT-OFF" COMPLETELY ABSORBED INTO THE FLOW.  A SURE SIGN THAT THE NORTHERN STORM TRACK IS BEGINNING TO EXERT ITS DOMINANCE ON THE WEATHER ACROSS THE GREAT LAKES AND OHIO.  THIS ALL MEANS MORE SMALL, FREQUENT SNOWS WITH SUBSEQUENT LAKE EFFECT SNOW.




REMEMBER THE ARCTIC OSCILLATION AND NORTH ATLANTIC OSCILLATIONS?  THEY SEEM TO BE TRENDING LOWER. THIS POINTS TO A STRONGER NW FLOW WITH MORE FREQUENT COLD BURSTS LASTING A FEW DAYS AT A TIME. THE LEVELS AREN'T POINTING AS LOW AND AS COLD AS LAST WINTER BUT ITS A TREND DOWN NONETHELESS.




WHAT WE WILL NEED TO LOOK AT CLOSELY IS THE ARCTIC OSCILLATION IN THE MIDDLE OF JANUARY.   IF A MAJOR COLD AIR OUTBREAK WERE TO OCCUR, THE ARCTIC WILL SHOW SIGNS OF IT AND THE "AO" WILL NOSEDIVE LIKE LAST YEAR AND IN 2009.

Arctic levels dropped VERY low in December

2010 arctic levels drove temps well below normal early in the winter
REMEMBER:  SINCE 1950, 15 OF THOSE 60 NOVEMBERS AND DECEMBERS HAVE HAD LESS THAN 10 INCHES OF SNOW.  THAT'S 25!  THE JANUARY'S THAT FOLLOWED AVERAGED 14 INCHES OF SNOW FOR NORTHERN OHIO (NOT COUNTING LAKE EFFECT AREAS). 
 
THAT IS THE EXACT AMOUNT THAT MY COMPOSITE SHOWED LAST WEEK! 

I GUARANTEE SNOW FOR JANUARY WITH MORE FREQUENT COLD SPELLS. SNOWS WILL BE ALBERTA CLIPPER IN ORIGIN. 


THE LAKE IS STILL WIDE OPEN AND I DON'T THINK IT WILL FREEZE THIS YEAR. THIS MEANS THAT ANY COLD AIR WHICH FOLLOWS THESE CLIPPERS FROM THE NORTHWEST WILL SURELY CREATE LAKE EFFECT SNOWS.

WINTER-LIKE TEMPS ARE CLOSER THAN WE THINK!

Volcanoes: A Year in Pictures

2011 was a year of extremes both in the weather and geology.  I ran across some great pictures posted on theatlantic.com back on December 16th highlighting the eruptions of some of the world's most active and INACTIVE (until recently) volcanoes. (Credits: Reuters, AFP, USGS, Getty Images, AP)

Here they are in no particular order:

Volcano, Hawaii

Southern Argentina

Vatnajokull, Iceland
Grímsvötn volcano

Indonesia's North Sulawesi province

Kilauea Volcano, Hawaii

Mount Bromo, Indonesia

Mount Etna, Sicily

Puyehue Volcano, Southern Chile


Miyazaki and Kagoshima prefectures, Southern Japan


Kilauea Volcano, Hawaii

Tuesday, December 20, 2011

January 2012 Outlook - Readers Digest Version

After re-reading the January Outlook I posted yesterday, I realized that the post was somewhat convoluted. 

Ok, it was alot convoluted!



As I ran through how I came up with the resultant composite for January, it hit me that the post read more like a Stanley Kubrick script than a straight-forward outline.  So here we go one more time.

Have we had any Novembers and Decembers similar to this year when we look at the indices that describe the state of the ARCTIC, NORTH ATLANTIC, ATLANTIC AND THE PACIFIC?  Yes.

PNA (Pacific Index) = 1970, 1973, 1994

AO (Arctic Index) = 1994
Dropping the AO a bit, we get these years =
 1975, 1979, 1982, 1990, 1992, 1994, 2004, 2006

NAO (North Atlantic Index) = 1982, 1986, 1992, 1993

PDO (Pacific Ocean Temps) - September-December averages similar to this year = 1999, 1994, 1961, 1955, 1950

AMO (Tropical Atlantic) - October-November drops similar to this year =
                1987, 1963

The year that matches up the best (NOV and DEC) = 1994

Let's assume (BIG ASSUMPTION) that January's indices will drop to levels that are more conducive for "typical winter weather"--not huge drops but just enough.  That is the ARCTIC DROPS SLIGHTLY NEGATIVE, THE PACIFIC ALLOWS THE TROUGH TO PUSH A BIT FURTHER EAST AND THE NORTH ATLANTIC ALLOWS FOR MORE NORTHERLY STORMS, WE GET THESE JANUARY YEARS FOR OUR COMPOSITE:

1987 (El NINO), 1963 (WEAK LA NINA)

Since the PDO (pacific ocean temperatures) are at the lowest since December of 1961, the years 1955 and 1950 have to be factored more heavily.

That gives us:  1987, 1963, 1955, 1950

Here are the composites for these years weighting 1987 and 1963 highest because they match this year's daily indices the best.



Remember that there are no PERFECT MATCHES.

First NOVEMBER'S match then JANUARY of 2012. 

BTW, My January snowfall outlook: 14 inches!




STORM TRACKS FOR JANUARY
TEMPERATURE OUTLOOK. SLIGHTLY BELOW NORMAL
There. That works much better!

Monday, December 19, 2011

Why the Mild Early Winter? Updated January Outlook


Most of everyone were anticipating a sharp and cold start to the winter. That hasn't happened.  This winter is sure not shaping up like the winters of the last two years. Here are the reasons why we missed it and what we can learn from it. I often like to post the reasons we come up with the forecast so that you can understand our thinking. Forgive me for being technical in the post. Its wordy but it illustrates the "why" in our weather fairly well.

The lack of snow with almost 7 inches of rain since November 1st is the result of underestimating a few factors:  The Pacific Ocean temperatures, The stable Arctic and the resurging La Nina in the tropical Pacific Ocean.

First the Pacific Ocean Temperatures.

I indicated in my previous blogs how the Pacific Ocean temperatures are cooler than last year along the west coast/Gulf of Alaska driven by the warm pool in the central north Pacific sliding east. The ridge east of the warm pool kept the trough out west and the eastern US ridge ridge over Ohio has kept temps above normal with little snow making fronts.

The Stable Arctic: In this blog post a few weeks back, I talked about the "Arctic Oscillation" which measure the stability of the arctic cold. A positive number means the arctic air is locked up north and very stable. A negative number means an unstable arctic cold air mass meaning it has a much better chance of slipping south.  Last year, the arctic was VERY unstable. So far this month, the arctic oscillation is strongly positive. The strongest positive December number since 2006; it might be the highest since 1950 by the end of the month!



Lastly La Nina:  All measures of the La Nina (colder than normal temperatures in the tropical Pacific) show this second La Nina to be far weaker.  While most La Nina feature "Alberta Clipper" type snows (2-4 inches at a time), this La Nina so far has featured the southern Jet Stream as the main driver.The main reason we've had more than 7 inches of rain since November 1st.


Now that we've learned our early season lesson of not underestimating these factors, how can we apply these newly found points into formulating an updated January Outlook?

1) Currently, the computer projections indicate that the ridge/mild weather over the east will break down a bit late this month and early January.  Using the current levels for DECEMBER and the final levels for NOVEMBER which measure the PACIFIC and the STABILITY of the ARCTIC, we come up with only one matching month and year:  

January of 1995That January we received 23.4" of snow.

Since one year isn't a good, unbiased indicator (January 1995 was an El Nino month) Are there any January years that match up a bit better?  I think there are.

First, let's assume that the western trough slides east EVEN SLIGHTLY.  That said, there are only 12 January years where the PACIFIC INDEX going slightly positive and allows the trough to push into the Great Lakes while the stability of the arctic drops only slightly negative

These year are: 2010, 2001, 1998, 1987, 1985, 1977, 1970, 1963, 1961, 1958, 1953

 If you count the years where the North Atlantic Index becomes slightly negative allowing for more Alberta Clipper Snows, you get:

2010, 1987, 1985, 1977, 1970, 1963, 1958

Since this year's Pacific ocean (cool temps) is a bigger player than in some of the past years on this list. I eliminated 1970 & 1977 (milder Pacific Ocean temps), 1958 (El Nino Year) and 1985 (Atlantic Ocean temps different) added 1950 and 1955 because these two years featured very cool Pacific Ocean temps similar to this year. 

This La Nina is weaker than last year so I eliminated 2010.

The final list of year used in formulating January's outlook are:

1987, 1963, 1955, 1950

I weighted 1987 and 1963 higher. I also weighted 1950 and 1955 but not as high.

This gives us: 14 inches of snow for January for Cleveland. Slightly more in the snowbelt!

The result is this:  Notice the shades of blue indicating the trough out west sliding a bit east over Ohio. Compare this with November's map where the shades of blue were mainly out west.
How about temps? They should trend slightly below normal but not by much

Where will storms originate? Southern panhandle systems will still be a problem. Clipper snows will be more frequent.
The bottom line is that analysis is the key to weather patterns. There is never a best fit year or month to the current setup especially this year.  I still don't see any large scale cold air drivers. Cold air in spurts will continue. I have a feeling that the kids will be using one of their snowdays in January!

Friday, December 09, 2011

1st Snow on Dec 9th--What About the Other Snowless Decembers of the Past?

Finally our first real, widespread snow and its already December 9th. Most people have finished putting up Christmas lights.


A far cry from last December when we had snow on the ground almost everyday with the average high temperature well below freezing. 
3 inches of snow in Sharon Center, Medina County
How does this overall "winter-less" pattern compare with the least snowiest Decembers going back to the late 1960s? First, here are the least snowiest Decembers in chronological order:

1965: 1.2"
1967: 2.8"
1971: 1.9"
1978: 2.5"
1986: 1.1"
1994: 1.0"
2001: 3.7"

The answers to our pattern lie in the winds aloft. They establish the direction the storms along with the propensity for storm development in certain locations. Often times, these "locations" or dips in the wind field are established/enhanced by the warmer/cooler ocean temperatures. These ocean/atmosphere connections are felt "down stream" here in Ohio as either a cold or warm pattern.

Below is the first year: 1965. The map on the left shows where the HIGHS and LOWS are located. The right map shows the COOL and WARM pool in the Pacific and Atlantic and their positions. Notice the HIGH near the WARM POOL in the PACIFIC and the HIGH over the great lakes. In between lies the WESTERN trough where the LOWS reside. This HIGH kept warmer than normal air over OHIO and the snow amounts small.

Now 1967, 1971, 1978, 1986, 1994 and 2001. Notice that the PACIFIC HIGH is near the WARM POOL in each year and the WESTERN trough sits ahead of it. Also, notice the LOW in the ATLANTIC in varying degrees each of these Decembers. For OHIO, the same RIDGE we have overhead this year suppressed the COLD and SNOW in these past years.

When we average all of these years, we come up with this composite picture. Notice once again, the HIGH over OHIO.  
November this year, featured the strong PACIFIC HIGH which drove COLD AIR into the WESTERN TROUGH which kept the OHIO RIDGE in place keeping us mild and wet. Look at the similarities between  this past November picture below to the Decembers above.  Scary isn't it?
 Now look at the first week of December through the 7th. The HIGH has shifted north into ALASKA shifting the WESTERN TROUGH east into CANADA and the CENTRAL US which has drove the OHIO RIDGE well east.

Does this still mean December will stay below normal in snowfall or are we anticipating a shift to a colder pattern? I have a good feeling that this December will feature more short-lived cold shots and off/on snow. Will it be as snow less as the Decembers above?  Given these pattern shifts and the ATLANTIC shifting cooler, we can expect weather that is more winter-like. Meanwhile, I'm off to cut down a Christmas tree!



Wednesday, December 07, 2011

Dec 7th Snowcover Last 5 Years: Which Year is the Winner?




Our first lake effect event begins Friday.  So far, hardly a flake has fallen this year. Has this year's snowfall country wide more or less than in recent years?  Here are the numbers with these excellent snow maps from the National Snow Analysis site. from this year back to 2007. Last year and this year are dead-even. Notice the snow this year is west whereas last year, it was east.