Make no mistake about it, the last month the weather has been about as exciting as watching paint dry. The "death ridge" remains a dominant force that quite honestly is a point of concern. Week after week the models keep trying to show it breaking down but when push comes to shove, it's still there and it's stronger than ever.
Here's the 500mb forecast for this weekend (Nov 26th)
The death ridge is centered directly over the Rockies. I call it that because there's no moisture associated with the pattern. The fast moving storm track does not allow short waves (or storms) to amplify or acquire moisture until they reach the east coast. The kiss of death for storm development.
Here's the PWAT's (precipitable water vapor) that's forecast Sunday the 26th coincident with the 500 pattern above. PWAT's in the upper Midwest are 0.10", similar if not less than what is found in the deserts of Arizona! You can clearly see what moisture there is located within the troughs situated over the east and west coasts (purple colors).
This has left much of my area without rain or snow of any consequence since about the 23rd of October. Since then only one disturbance has brought more than 0.13" of rain, that system managed to squeeze out .36" on November 19th. Whoopie!
Looking for a change? Well don't get your hopes up any time soon. Here's the surface pattern December 1st. High pressure essentially covers the majority of North America.
Now the surface pattern for December 6th. Not much different than the 1st.
Without some radical change in the models, I can't begin to stress how dry that looks for the next 14-20 days. The EURO certainly agrees showing this for 10 day total precipitation.
Here's a closer perspective of my local area.
Just look at the projected 10 day snow totals on the EURO. It's pretty likely that there will be no snow on the ground in my area going into December.
Needless to say this is very troubling for a guy who likes his snow. Once again I say we need to get this turned around quickly. I said that a week ago and so far nothing looks much different going into the prime snow months of December-February. I'll be honest, I'm worried about where this is going.
By now I would have hoped snow cover would extend well into the Dakota's, Minnesota, and Wisconsin. As it is, there's not much to be found with only 13% of the country covered with an average depth of less than 1 inch.
The lack of snow cover modifies cold air masses as they push south out of their source regions in Canada and the Arctic. That also aids in keeping the snow producing jet stream further north. It's no mystery that snow not only breeds cold, it leads to its production.
So what needs to happen to change the game? The one thing I would like to see is blocking in Canada and Greenland. That would constitute a negative NAO (North Atlantic Oscillation). That creates storm tracks that deliver both snow and cold over the central and eastern U.S.
Another factor which should come into play is the QBO. The quasi-biennial oscillation (QBO) is high level wind at the very top of the atmosphere (30 mb) that exists over the Equator that oscillates from East (negative QBO) to West ( Positive QBO) . A full cycle can take anywhere from 18 to 30 months . The strongest Positive values are usually around +15.00 or so while the strongest Negative values will exceed -25.00 or so. The QBO winds work there way down to into the Lower levels and affect weather patterns. This year forecasts are for a negative QBO and that combined with a weak to moderate La Nina is a strong indicator for cold in the central and east. Here's an estimate of what winter temperatures look like in a negative QBO of -10/-15.
I also talked about the La Nina. The cold water in the tropical Pacific that constitutes it is eastern based near Peru. What we've found is that this type of La Nina tends to be followed by colder winters in the upper Midwest. Take a look
Despite the gloomy look of the pattern today (it's horribly boring), I still see drivers that keep me optimistic winter will find its MOJO at some point in December. I can't hear the fat lady singing just yet! Roll weather...TS