Friday, December 23, 2011

Personal Winter Forecast: Bondville VT, Bethel CT


Precipitation: Slightly Above Normal
Temperature: Above Normal
Snowfall: Below Normal

While Precipitation should be slightly above normal, above normal temperatures should help make for some below normal snowfall as the positive NAO will likely prevent the big snowstorms.


Precipitation: Slightly Above Normal
Temperature: Above Normal
Snowfall: Below Normal

Refer to the above discussion.

Not Banking on December 27 Northeast Snowstorm

The teleconnections just aren't in the favorable territory for a late December snowstorm for the Northeast. Among the most prevalent is the positive NAO and the raging positive AO.
Past NAO and AO indices.
The NAO has been on a mixed path this fall, up until about November 20th, when the NAO took a turn for the positive territory. Since then, the NAO has not managed to get into negative territory, which has hurt the Northeast's snow chances. As of right now, the NAO is entering a raging positive phase. This is typically hard to break, and even with a sudden change that would bring the NAO down to negative territory, this process would take at least 3 days. Because today is December 23, and the storm is supposedly on the 27th, I do not believe that the NAO will be able to dip into negative territory fast enough in time for a snow event in the Northeast.
A typical NAO features a high pressure over Greenland, leading to a dip in the jet stream over the Northeast, where storms would move around the Northeast region and produce snow for that area. The new 18z NAM is showing pretty much the opposite, with a ridge of high pressure affecting the Northeast and instead pushing the jet stream north. The 27th storm then dumps a few inches of snow on Illinois, Indiana, unable to get to the Northeast due to the high pressure. I am liking this solution, as the NAO should still be positive enough to influence these conditions.

The Arctic Oscillation (AO) involves a vortex (spinning) of air over the Northern parts of the NH (North Hemisphere). When this vortex is unusually weak or nonexistent, the AO is said to be negative. Cold air then flows south into the US. However, when this vortex is strong, the cold air is literally locked in that space where the vortex covers. Until that vortex weakens, the cold air is forced to stay north. As of right now, we see the AO moving into a strong positive phase. Like the NAO, this is hard to break. Because it will likely be still positive on the 27th, not enough cold air would be present, even if the storm managed to squeeze into the Northeast. I could see a rain event being the outcome.

It's just not a good combo of teleconnections right now for this storm. I am not supporting the idea of a Northeast snowstorm, but do feel that there is potential for the Great Lakes to get some snow rather than the Northeast.

Personal Winter Forecast: Raleigh NC, Traverse City MI, Springfield IL


Precipitation: Below Normal
Temperature: Above Normal
Snowfall: Below Normal

The Positive NAO will provide grounds for North Carolina to not get the biggest of storms this winter, thus the below normal snow and precipitation. However, that doesn't mean that some big storms won't hit the Northeast. Temperatures will be above normal as a warm fall continues into the winter.


Precipitation: Around Normal or Slightly Above Normal
Temperature: Above Normal
Snowfall: Ending Normal (Or Going Either Slightly Below/Above Normal)

Michigan could go either way with snowfall, as precipitation isn't too confident right now. Temperatures will probably be above normal, going off the warm fall for the entire Great Lakes region and Midwest.


Precipitation: Slightly Above Normal
Temperature: Slightly Above Normal
Snowfall: Around Normal*
*Confidence is Lower Than Normal

Springfield will likely see some above normal temperatures and precipitation. The storm track is right around normal, while temperatures have been warm through the fall. Snowfall might end up around normal, but confidence is unusually low.

SIGNIFICANT Stratospheric Warming Indicates Pattern is Changing

10mb stratospheric temperature

30mb stratospheric temperature

50mb stratospheric temperature

70mb stratospheric temperature
The Long Awaited Pattern Change may be At Hand!

Significant stratospheric warming, bigger warming than what we've seen all year, is occurring in the parts of the stratosphere that haven't experienced as much warming as areas like the 1mb, 2mb regions of the stratosphere. Because those 1mb and 2mb regions are more prone to warming than the areas we posted in the images above, it means that the pattern change may occur faster than usual. It matters if the warming is close to the 100mb level, and right now, the stratospheric levels closest to the 100mb level are experiencing the most significant warming.
If you're wondering if the cold and snow is coming, the answer is YES. This appears to be the breaking point for the stratosphere. Each day that continues with the significant warming is an even better chance of a bigger and faster pattern change. We are very optimistic about this new development, as this is the biggest sign yet of a possible pattern change. Stay tuned!

Personal Winter Forecast: Westminister MD, Tanytown MD, Southwest Harbor ME


Precipitation: Slightly Above Normal
Temperature: Above Normal (At least +2 degrees above normal)
Snowfall: Below Normal

A dismal start to winter has had its effect on the Northeast, with warm temperatures and below average snowfall expected.


Precipitation: Slightly Above Normal
Temperature: Above Normal (At least +2 degrees above normal)
Snowfall: Below Normal

Because this town and the one above are in the same state, refer to the previous discussion for Westminister.


Precipitation: Slightly Above Normal
Temperature: Slightly Above Normal to Above Normal
Snowfall: Below Normal

This will not be a good winter for snow lovers all around, as Maine is likely to receive below average snowfall as a consequence for this dismal start to winter.

PATTERN CHANGE Finally Starting!

BIG UPDATE as SIGNIFICANT stratospheric warming is observed at ALL LEVELS of the stratosphere monitoring!

Personal Winter Forecast: Brighton MI, Mora MN, Kent OH, Ellicottville NY


Precipitation: Above Normal (At least +1 inch)
Temperature: Around Normal*
Snowfall: Ending somewhat around normal*
*Confidence is lower than usual.

Michigan is relying on this pattern change. If it happens, temperatures will cool off and snow will come alive. However, we had to put the lower confidence asterisk because of how the temperature and snowfall indices rely on this pattern change that might not be present in winter long enough to have any effect.


Precipitation: Around Normal
Temperature: Cold (At least -2 degrees below normal)
Snowfall: Around Normal*
Confidence is lower than usual.

Precipitation and snowfall are also reliant somewhat on the pattern change. Should the pattern change occur, the snowfall and precipitation would be in a much better condition for confidence.


Precipitation: Well Above Normal (Threatening Records)
Temperature: Ending Slightly Above Normal
Snowfall: Ending Around Normal or Above Normal

Ohio has been breaking precipitation records, and with more rain coming, it is only anticipated that more records will be broken. Temperature is a tough field- Ohio is in the same boat as the Northeast, which is above normal for temps, but if enough cold shots come down, they may end up slightly above normal.


Precipitation: Above Normal (At least +2 inches)
Temperature: Above Normal (At least +2 degrees)
Snowfall: Possibly Below Normal*
*Confidence is lower than usual.

A warm fall is leading into a warm winter this time around. If the pattern change comes around, we may be able to change that snowfall to better grounds, as may the precipitation, but for now, it's all about the warmth.

Up to 12 Inches of Snow for New Mexico Possible - Posted 12/23

UW-NMS Model with 6z NAM Initialization
There is potential for up to a foot of snow to fall in New Mexico in the next 48 hours as a storm system moves along the Mexico/US borderline. It appears that this heavy snow will be more in an isolated area, as the system puts its energy into a specific spot for the heavier snowfall.
We should be seeing a low pressure system dump snowfall in New Mexico, Mexico itself eastward into Texas. Amounts in Texas will be nowhere near what they were in the Blizzard a couple days ago. Farther eastward, a lack of colder air will lead to precipitation in the form of rain.