Space Weather

Friday, March 15, 2013

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...

 
  00zecmwfwestnao
                                  
                                      Here is the Euro NAO outlook going to the end of March.





18zgfswestnao
       
                                                         Here is the GFS NAO outlook




AO:
ao_mrf

 
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:
 
 
   pna_mrf  
 
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     
                                                                                                                                         
                                                                               SST’s



    figure6  

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.

Omaga block


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


No comments:

Post a Comment

Thank you for taking the time to comment, I will answer as soon as I can.