Winter Pattern Unrelenting: More Arctic Cold

Our winter weather outlook back in late October featured a below normal temperature (much colder winter) with above average snowfall.  Given the weak central based El Nino, cool pool in the northern Pacific, warmer west coast and warmer east coast, a stronger southern jet stream phasing in with the polar jet to the north driving big snowfalls from nor'easter type storms in New England shouldn't be surprising.

The areas of the ocean that went into our winter outlook are circled in red. All pointed to colder than normal temperatures in the east.

This is different from last winter when the warm west coast cool of ocean was located in the north central Pacific near the Gulf of Alaska. The central based El Nino (Modoki) hadn't developed yet.

I want to emphasize that these warm and cool pools aren't and weren't the only drivers of our last two winters. But they are significant. Here was our initial best match as we formulated out winter weather outlook (December through February temperatures) back before Halloween.

The overall pattern remains very cold. More cold this weekend--Polar Vortex type cold!

Well below zero across much of the northeast Friday and especially Sunday morning. Even Florida will see lows in the 20s Sunday morning (February 16th) from Jacksonville to Pensacola. The orange crop might take a hit!

Below zero wind chills will reach northern Georgia and the Carolinas with -20 to -30 chills across the Great Lakes.

Here we are in mid February when the cold usually starts to retreat as the first pushes of spring emerge across the deep south. Will the cold air break sooner or later?

The often overlooked Canadian model shows the trough east/cold east continuing through the end of the month. The other models show this too.  However, the trough is retrograding back west a bit. This would shift the cold into the Great Plains by the end of February.

Cold Pattern thru end of February

In droughts, extremely hot conditions will feed off of the extremely dry air above the dry ground. This creates more evaporation which feeds the heat. This chain reaction is very hard to break. In perpetually cold patterns like this, the drivers are very strong and very difficult to break. The cold air can feed the upper air pattern reinforcing the trough in the east and cold/ridge and warmth in the west. In essence, the overall pattern remains stuck.

Good news is that heading into March even during the coldest Marches in Cleveland, 60+ degree warmth shows up by the middle of the month.

That said, the southern branch of the jet becomes very active in March. This could lead to a few more panhandle type storms in March which always have potential for reach Ohio.  Stay tuned.

Digging Deeper For Signs Of The Next El Nino

After reading several posts which posed the question of whether a "Super El Nino" will develop this summer, I wanted to find more data to shed light on what to look for in the upcoming weeks. These articles have sited sea surface temperature comparisons to 1997 both on the surface and below, ocean heat content, the building Kelvin Wave and subsequent changes in atmospheric winds.  All seem very valid. Let's review:

Comparing the sea surface temperatures on March 24th of this year to 1982, 1997 and 2002 (a weak El Nino year), each shows some warming in different locations at least on the surface. I circled the area in question in red. This is why we can't use a two dimensional sea surface temperature map as the only El Nino indicator.

 

Ocean Temperatures have been climbing in the western Pacific over the last 30 days. Notice the bubble of warmth between 100 and 200 meters.

Sub surface heat continues to build since the beginning of the year (see above). It compares very well to the onset El Nino of 1997. The Australian Bureau of Meteorology shows this very well.

HUGE spike in near surface ocean heat last 4 weeks

2002 was a weak El Nino year. The subsurface heating was nowhere as warm.

Comparing the sea surface temperatures on March 24th of this year to 1982, 1997 and 2002 (a weak El Nino year), each shows some warming in different locations at least on the surface. I circled the area in question in red. This is why we can't use a two dimensional sea surface temperature map as the only El Nino indicator.

The Southern Oscillation Index (Pressure index comparing sea level pressure at Darwin, Australia to Tahiti--30 day monthly moving mean) suddenly dropped into heavy El Nino territory.

Yet one index that blends together BOTH the changing ocean characteristics and the atmospheric conditions above it hasn't caught onto the idea...at least yet. Interestingly I haven't found much mention of this. This is called the Multivariate ENSO Index. The index includes several elements into its index: Sea surface temperatures, wind speed and direction, sea level pressure and temperature along with total cloud cover/fraction of the sky. Details are here on ESRL SITE.  Similar to the ONI Index, the MEI Index is calculated using overlapping 2 month periods. Since it takes into account many other atmospheric variables, the El Nino or La Nina signature may lag a bit compared to the others But in my opinion, it gives a better overall representation of the ENSO state even though it might be late to the party.

So far, the MEI is far ahead of 1982 and 1997, yet no positive numbers have shown up. Remember that The MEI is an overlapping bi-monthly indicator. So when the April update comes out (probably the first week of April), it will illustrate the conditions (ocean and atmospheric) for the FEBRUARY-MARCH overlap. If a  significant El Nino is truly developing, a SIGNIFICANT JUMP in the MEI would indicate it THIS SPRING as it did in 1982 and 1997. Check out the chart below for the past trend.

Be careful, the 1986 and 2002 MEI trends were SIMILAR to this year. Those years were weaker El Nino years.

Notice the MEI trends in 1986 and 2002.  Where will the MEI end up this summer?

So what's going to happen? Will the MEI match up with the MEI indices of the past El Ninos circled in black above. Will it mirror 2002 or 1986?

How will this effect out summer weather? 

The next 6 weeks will tell us a great deal.