Wednesday, November 7, 2012

Sunspots Drastically Below Forecast

The latest observed number of sunspots through October shows that the forecasted number of sunspots is much too high for what we have observed in the past few months.

This image is composed of raw observation data of sunspots, marked by the dots on the chart. The blue line on the left half of the image is the average number of sunspots through the observed period- basically the mean of the raw data. The red line is the forecasted sunspots. As you can see, it is pretty high compared to the observed sunspots.

What does this mean? Why would the sun affect me?

Temperatures are greatly influenced by sunspots- "greatly", meaning about a degree of wiggle room. A degree above or below normal across the nation is pretty big, considering it's the entire world's temperature average. All that aside, a lack of sunspots leads to a general drop in temperatures. Nothing significant by any means, but big warm-ups may now be a little cooler than they would be in average sun spots.

This is definitely something to watch in coming weeks that could affect temperatures, even through the winter.


Thanksgiving Likely to be Cool, Wet as MJO Shifts

Forecasted MJO off the NCEP

Precipitation anomalies in Phase 1 of the MJO. Green is above normal,
brown is below normal.

Temperature anomalies in Phase 1 of the MJO. Blue is below normal,
orange is above normal.
The time period close to Thanksgiving is looking cool and wet after an expected warm-up in coming days as the Madden-Julian Oscillation, or MJO, cuts around to Phase 1 by the last 2 weeks of November.

The MJO involves convection in the Indian Ocean/Pacific Ocean. The phases are determined by placement of precipitation, and each phase has a different effect on the United States. Phase 1 is typically considered among the best phase for snow lovers in the winter, as it is known to incite below normal temperatures and above normal precipitation across the central and eastern regions of the Lower 48.

If you have been watching my posts recently, you may have heard me mention something called the Rossby Wave. It involves storm systems moving south from the North Pole over the general same area. This time, the Rossby Waves will be in place over the West US, which will likely bring about warm conditions in the East. However, the good thing about Rossby Waves is that they are not persistent storm systems, meaning they hit the area they are supposed to, and then leave before another one takes its place. This, in turn increases the storm activity over the nation in this scenario.

If I use the MJO, Rossby Waves and my LRC winter forecast, I find it possible for the Midwest, Ohio Valley and Northeast to be up against a fairly strong storm system on Thanksgiving.


Long Range Lookout: November Lost to Warmth

I believe that November is, unfortunately, lost as far as winter potential goes, as a poorly-timed Rossby Wave train begins to set in for November.

Hour 204

Hour 384
The Rossby Wave train is a 'train' of storm systems pushing southwest from the North Pole. What happens in response to storm systems pushing in the West? If you guessed a warm East US, you are correct. Hour 204 from November 6th's latest GFS Ensembles shows that scenario.

Rossby Wave trains typically have a full cycle in which 3 stages occur. Stage 1 involves the pattern in a dormant state, not really doing much. Stage 2 is when you start to pick up on some storm systems hitting the same area over a period of time. Stage 3 is the full-blown active stage, as is forecasted in Hour 204 and 384. These three stages usually happen within a 4-6 week cycle, so it's no surprise that the farthest GFS Ensemble forecasts still show the Rossby waves in action.

Because this will be developing in early November, we can expect this poorly-timed pattern to last through November, likely ending in early December at the earliest and mid-December at the latest.

But don't lose hope!

I have been tracking this Rossby wave train for a while now. If I extrapolate (use observations in a forecast) this Rossby wave train will progress into the North Pacific. In response, the high pressure tendencies will be placed over the West, leading to a much stormier, colder pattern for the East. Couple that with favorable late-winter signals from Siberia in October and it looks like we could have a more back-loaded winter coming up.