Spring 2013 outlook part two.

OK here is part two to the Spring outlook for 2013. As with any seasonal outlook it looks at the overall setup, then tries to give a broad spectrum analyses, to anticipate what the season will be like. What it doesn't do, is give any details on individual storms or events.

Part one of the outlook dealt with the temperature outlook for Spring 2013. Part two will deal with precipitation/drought and severe/tornadoes.

Part one can be found here. 

Drought/ precipitation:

As most of us are aware, the weather pattern for this March is immensely different than last March. It was the same for Winter 2012-2013 when compared to Winter 2011-2012. While first half of Winter 2012-2013 was mild; the second half was anything but, the warm snaps gave way to waves of cold moving out of Canada. The pattern was very active with coastal storm after coastal storm hitting the region, resulting in most areas in the Northeast seeing average to above average snowfall.

With this year's average to above average snowfall for the vast majority of us; the Northeast has reversed the drought conditions from last year.

The snowpack will translate to a more favorable environment during the growing season for agriculture in most areas across the Northeast.

For the nation's midsection the picture is not so bright. The Heartland is enduring the worst U.S. drought since the Great Dust Bowl of the 1930's. So while recent rain and snowstorms across the Plains was welcomed with open arms; The impact will be fleeting. 

Unfortunately, the National Oceanic and Atmospheric Administration (NOAA) April, May, June precipitation forecast indicates equal chance of either above or below normal moisture, but a better chance for greater than average temperatures. All this would do is aid in increasing dryness of the soil in the Midwest and Southern Plains.

 But as I said, the outlook is much better for the Northeast. Because of the cold hanging around longer, we will see lower soil temperatures which will cause lower evaporation rates. Also there will be less danger of cold snaps that would kill budding, which was not the case last year. Last year many of us loss plants in the garden. Also the trees budded very early, only to lose them to a cold snap, which put stress on the trees in the Northeast.

   

NOAA precipitation outlook for Spring 2013

   

NOAA temperature outlook for Spring 2013  

If you look at the chart you will see MA, VT, NH, and ME along with the rest of the region, are labeled EC, which means the Northeast has as much of a chance to see above average precipitation, as it does below average. But I think, the Northeast should see average precipitation This combined with the deep snowpack will allow for much more available water for personal, agriculturally, and recreationally. This should keep this year's Northeast fire weather outlook under control.

   

The amount of snow in the higher elevations is shown here.

   

The snow/water equivalent is shown here  

Of course snow has to melt. As you can see the Tug Hill, Adirondacks, and White and Green mountains have a lot of snow. So what about the flood outlook?  Right now it looks like the potential for flooding due to snow melt is near normal. But it is pushing the high end across the Tug Hill and Mountains.

 

The amount of snow water equivalent shown on the map is about normal. Also, there are a few ice jams across the region. But right now they don't pose a hazard. However, the current pattern is quite active, with the cold air hanging on into April. Any snowstorms that do occur could tip the balance. So things will have to be watched.  

Severe/tornado:  

 

The average number of tornadoes per year in the U.S. is around 1,300, according to the Storm Prediction Center.  

 

The unusually quiet tornado season of 2012 was a complete reversal of record breaking tornado season of 2011. Last year the tornado season was very active in December into March We saw the record breaking Christmas outbreak. January saw another very large outbreak. But that ended just after April 14. On April 14,2012 we saw a major tornadic outbreak, which included dozens of tornadoes in Kansas. But, going into the rest of Spring and the Sumer tornado activity fell off sharply; by year's end, there were fewer tornadoes than ever on record.  

 

Tornado season varies with region. The tornado season tends to move northward from late winter to mid-summer. The deep south and down toward Florida getting their season in late fall to early Spring. In the Southern Plains, it lasts from May to early June. And in the Northern Plains, upper Midwest, and Ohio River Valley April through June, For the Northeast peak season is in last part of May into August. Tornadoes are most common in general from the months of April through June.  

 

If you follow my Facebook weather page, you know I talk about the Tornado and Dixie Alleys. But in-case you don't know where those are:  

 

Tornado Alley refers an area on the Plains going north to south that covers the northern region of Texas, Oklahoma, Kansas, Nebraska, Iowa, the eastern edge of Colorado, southwest tip of South Dakota and the southern edge of Minnesota.

 

 In the Gulf Coast region, Dixie Alley refers to West Tennessee, West Kentucky, North Mississippi and North Alabama.
  

A post I did in 2011 goes into detail on tornadoes and how they form. It can be found here.  

 

This Season:  

 

Severe weather season this year will be different from last year, ENSO neutral conditions tend to favor slightly above-normal severe weather in the Midwest and South. We can expect more damaging wind events, like derechoes. The long-range models are showing that a more prominent low-level flow of moisture will be present from the Gulf, feeding the complexes farther north over the Plains. This could aid in the formation of tornadic supercells.  

 

Once we get into April we should see severe weather over the lower Mississippi and Tennessee valleys.

The northwest flow over the Pacific Northwest and California, will continue. This should bring the storms further south, which should cause severe weather for Arkansas, Texas, Oklahoma, Missouri, Tennessee, Mississippi, and Alabama.  

 

Later in the season, severe storms could impact Ohio, Kentucky, parts of Indiana, and Illinois.  

 

This type of pattern favors seasons like 2010, 1974, and 2011. But, I don't think we will see the number of tornadoes we saw in 2010 or 2011  

 

The wild card is the ongoing drought. if it gets a lot worse this year. The dry air would reduce moisture and we would see a stronger then average cap over Tornado Alley........this would sharply cut into the number of supercells.  

 

So based on all of this I believe the number of tornadoes will be above average this season. However, it won't be record breaking.

  

Annual number of tornadoes by state  

 

The average number of tornadoes in the Northeast is 35-40; the vast majority of these occur in New York State and Pennsylvania.

 

The last few years have seen an uptick in the tornado count across Pennsylvania and New York. However, this year we should see more of an average season severe/tornado wise.  

 

Here is another post I did on severe weather safety. It can be found here.  

 

I have several post that deal with severe weather if you get a chance check them out.  

 

Well that's my Spring outlook…………Hope you enjoyed reading it.  


Rebecca

Spring 2013 outlook part one.

With Spring starting next week, it is time to take a look at the months ahead to see how might turn out. I will touch on  temperatures, drought, and the spring tornado season for the Country. I’ve never done a Spring outlook before. But I’ve been asked my thoughts on it. So I decided to write one up. Doing a Winter outlook is much easier than A Spring, Summer, or Fall outlook; This is because there a lot more variables involved….which is why most meteorologist don’t do them…. But since, God favors the foolish and fortune favors the bold, here goes.

About My Winter 2012-2013 Outlook:

But before I get stated, I want to talk a little about the Winter of 2012-2013. I just went back and read my winter outlook, and I gave myself a grade of B-.

If you are a regular reader of this blog, which I hope you are, you read my winter outlook. The outlook said, the first half of Winter would be milder and less active than the second half of Winter. I thought the winter would end up slightly below normal temperature wise for the Northeast. I also said, We had a good chance to see quite a few Nor'easter's.

I forecasted that the major Cities would see above average snowfall. I said " Northeast New York City, Philadelphia , Boston, and Albany will be in the corridor to see above average snowfall. While areas in Central NY, Western NY and PA, and the Tug Hill see more in the way of average snowfall. 

December will be noted for mild temperatures and lack of significant snow.

January started off very mild, as we approached mid January, some of you started to panic and said we were going to see a repeat of the previous winter. I tried to calm everyone by saying the teleconnections were showing a major pattern shift was on the way . Soon after this, we saw a lot of arctic air from Canada  move into the region, with over a week of very cold temperatures. However, this arctic outbreak still wasn't enough to make January colder than average.

February saw winter take a 180. The cold came back and for the most part stayed. We saw several snowstorms, that caused the month to end up among the top all time snowy February's on record.

 March has also been quite active cold and snow wise.  Philadelphia saw its snowiest March since 2009  Most of the coastal cities saw average to above average snowfall. Connecticut, Rhode Island and Massachusetts was more or less a mild but snowy one. Vermont, New Hampshire, and Maine, saw more or less average amounts.  summary, the trend of the past 10 years continues with less cold during winter, and snowfall to be slightly above the averages we have seen since 1872.  

Here is how the season was more or less in NYS.

Utica, NY has seen slightly below average snowfall this year.

The Golden Snowball Award is a contest between 5 cities in CNY – Upstate New York. The contest is based on which city receives the most snowfall for the snow season. These results came from the came from the Golden Snowball website

Golden Snowball Totals for the 2012 - 2013 Snowfall Season Updated 3/8.5/2013

GSB Cities	This Season	Normal Average to Date	This Time Last Season	Normal Seasons Average	All Time Season Snowfall Record
Syracuse.....	86.8	108.3	46.6	123.8	192.1 inches (1992 - 1993)
Rochester.....	67.7	84.5	55.6	99.5	161.7 inches (1959 - 1960)
Binghamton....	57.2	68.8	41.8	83.4	134.0 inches (1995 - 1996)
Buffalo.....	53.2	83.1	34.8	94.7	199.4 inches (1976 - 1977)
Albany.....	35.0	50.0	23.0	59.1	112.5 inches (1970 - 1971)

These snowfall amount were for Friday the 8th...a few more inches have fallen since then.  The Tug Hill region of NYS saw 120 - 200 inches of snow. Due to its size there is no official average across the Tug Hill..... But on Average parts of the Tug Hill, receives more than 200 inches a year.  You can read over my outlook...and decide for yourself how well or bad I did.

Because snow was still falling and more forecasted. I might add a section to this showing the totals for the 2012-2013 season, at a later time .

 Link to my winter outlook  

Ok, lets get into the 2013 Spring outlook.      

Teleconnections:    

NAO:

  

What is the North Atlantic Oscillation (NAO) index...it's an index that measures the state of the Atlantic...it involves the differentiation of pressure between Iceland and Greenland down to the Azores and over into Spain. The NAO helps to create blocking and helps to bring cold air into the northeast when in the negative phase...

 

 

                                  
                                      Here is the Euro NAO outlook going to the end of March.

       
                                                         Here is the GFS NAO outlook




AO:

 

The latest GFS ensembles have grown even more impressive on the re-strengthening of the ongoing blocking. They are suggesting that the AO could fall to between -5 and -4. I wouldn't be surprised to see it get close to -6.

 

 

  PNA:

 

 

    

 

Moreover, with the PNA forecast to be somewhat negative, that's also favorable for a colder outcome at this point in time. 83% of the March-April  snowstorms formed when  the PNA below 0.  

 ENSO:

  

ENSO stands for El Niño/ Southern Oscillation. The ENSO cycle refers to the coherent and sometimes very strong year-to-year variations in sea- surface temperatures, convective rainfall, surface air pressure, and atmospheric circulation that occur across the equatorial Pacific Ocean. El Niño and La Niña represent opposite extremes in the ENSO cycle.

 

 Global SST Departures  

During the last four weeks, equatorial SSTs were above average across the eastern Atlantic Ocean and near the Maritime Continent (north of Australia). SSTs were below average in the central and eastern Pacific Ocean

The ONI is based on SST departures from average in the Niño 3.4 region, and is a principal measure for monitoring, assessing, and predicting ENSO. Defined as the three-month running-mean SST departures in the Niño 3.4 region. Departures are based on a set of improved homogeneous historical SST analyses (Extended Reconstructed SST – ERSST.v3b). The SST reconstruction methodology is described in Smith et al., 2008, J. Climate, vol. 21, 2283-2296.)

El Niño: characterized by a positive ONI greater than or equal to +0.5°C.

La Niña: characterized by a negative ONI less than or equal to -0.5°C.

By historical standards, to be classified as a full-fledged El Niño or La Niña episode, these thresholds must be exceeded for a period of at least 5 consecutive overlapping 3-month seasons.

        

                                                                                                                                         
                                                                               SST’s

      

Equatorial sea surface temperatures (SST) are near average across the Pacific Ocean. Over the last couple months, the atmospheric circulation has been variable partially due to an active Madden-Julian Oscillation (MJO). Low-level (850-hPa) wind anomalies were easterly over the west-central Pacific. Weak westerly anomalies were present over the eastern Pacific. Upper-level (200-hPa) winds were westerly across the east-central Pacific. Over Indonesia, anomalous convection remained enhanced north of the equator and suppressed south of the equator . During the last month, below average SSTs have weakened in the eastern Pacific. Over the last month, the change in SST anomalies is positive in the eastern Pacific. Most models predict the persistence of current Niño-3.4 values, with ENSO-neutral (-0.5ºC to +0.5ºC) continuing through the Northern Hemisphere summer 2013. Therefore, due to the lack of persistent atmosphere-ocean coupling, slight ENSO-neutral conditions will be in effect for the Spring of 2013.    

Temperatures:

As I said, the vernal equinox will begin next week on the 20th. We do have warm air in the Southwest, in fact California is seeing record highs. If you've been following my Facebook weather page, you will know that I've been talking about strong high pressure between Northeast Canada and Greenland. This will act like an roadblock, slowing the systems as they approach the Northeast. And allows colder air to move down into the Northeast. Until the Greenland Block weakens, we will stay generally colder than normal.

A blocking pattern looks to develop to our north across Canada. Here is a 500mb GFS chart showing the 29th of March, I've drawn in the air pattern and the highs and lows. The red line shows the air flow moving around the pressure systems. This type of pattern is called an omega block. The Omega block will make it extremely difficult for the warm air to make it into the Northeast. So, with the active weather pattern we have a good chance of seeing more snow thru at least the end of March. Systems are stacked across the Pacific. This is one of the reasons the computer models have been having such problems with the pattern. There are singles that we could see a few cold/snow intrusions past Mid April as well.

The GFS and the ECMWF are both supporting the idea of the cold air staying in-place going into Spring. The AO and the NAO look to stay negative going into the first week of April. When these indexes are negative it often leads to a blocking pattern similar to what the 500mb chart shows. The Omega Block will keep the warmer air out of the northeast. However, the lack of a La Niña and predominant neutral ENSO conditions will probably result in a warmer spring than last year As I've shown in the with the models and the NAO and AO oscillation, April should start cold due to the blocking. But once, we get toward the middle of April things should shift toward warmer conditions as the spring progresses and neutral ENSO conditions prevail.

Due to the length of this subject, I will splint it into two parts. Part two will cover precipitation/drought and the severe/tornado outlook.



Rebecca