March 3 2012
AN EARLY LOOK AT ENSO
While it is very early to talk specifics when it comes to our summer forecast; there are some features one may look at, to get a general understanding to how the weather MAY shape up for the upcoming summer months. All winter long we experienced a rather STRONG La NINA event coupled with the lack of high latitude blocking which favored an extremely progressive weather pattern for the east coast.
This is a look at the LA NINA event through sea surface temps back in Dec.
 |
| Note the BLUE coloring over the Eastern Pacific indicating a moderate to strong La NINA event. |
Move ahead three months later....
On the left is an animation of the temperature depths from the surface (at the top) to 400m deep. Note the strong blues from Jan - Feb however there is now indications of warming mid way to the surface. What this tells us is the depth of cold water is recycling out due to weaker easterly winds.
The next question then becomes .. How strong? Well we will not know for sure exactly how strong the event becomes however, there area few NCEP models clustering between a weak to moderate event. An event by the way is classified as an anomaly greater then .5C over the eastern pacific. WHAT DOES THIS MEAN???
An ELNINO event this summer will lead to a reduced number of tropical systems in the Atlantic. This is caused by an INCREASE in Wind shear over the Carribean and Atlantic. Note the trend below.
| Atlantic | Eastern Pacific | |||
|---|---|---|---|---|
| Average | El Niño Avg. | Average | El Niño Avg. | |
| Named storms | 9.4 | 7.1 | 16,7 | 17.6 |
| Hurricanes | 5.8 | 4.0 | 9.8 | 10.0 |
| Intense Hurricanes | 2.5 | 1.5 | 4.8 | 5.5 |
In terms of extremes.. Well, there wouldn't be many. While there still will be an active Tornado year for tornado ally. The focus will shift over the N Plains by May and much of the summer as the Pacific Jet will retreat north. This will cause a VERY wet Pacific NW and Dry and warm SE.
MY THOUGHTS....
THIS IS TAKING JUST THE EL NINO SIGNAL INTO CONSIDERATION!!
Here's where I am at with this. First, I see us entering a El nino event or near close to it. If the event is weak (after coming out of a strong La Nina event) we could draw an analog comparable to 2009.
The summer of 2009 was Below average temperatures seen Below Here:
HOWEVER a slightly stronger event coupled with a positive NAO (which we saw all winter) could favor MUCH warmer temperature solution..!
