View Full Version : Rest of Nov - Dec Outlook

11-08-2011, 03:23 PM
Ok, here we go.

Public winter forecast: http://www.nynjpaweather.com/winter-forecast-for-20112012/

Not mine, but one of the best in the business, this guy has nailed the last 3 winters.

<span style="font-weight: bold"><span style="text-decoration: underline"> <span style="font-size: 14pt">Rest of November outlook. </span> </span></span>

<span style="font-weight: bold"><span style="text-decoration: underline"> <span style="font-size: 11pt">Highlights: </span> </span></span>
Warm temps with a short bout of cold over the next 15 days. (Go grab some extra rock time)

End of the month will crash into winter and it should hang on this time.

Iíd give decent ice by Thanksgiving about a 30/70 chance (not great, but not out of the question)

December is pointing to a stormy and cold month for the NE.

<span style="font-weight: bold"><span style="text-decoration: underline"> <span style="font-size: 11pt">Details: </span> </span></span>
The calling card winter pattern that setup to produce the epic October snowstorm in the NE has retreated. No worries, winter is not gone, or over by any stretch of the imagination. The big Bermuda high has been allowed to build over the SE US causing a trough in the West and ridge in the east. Pretty much the exact opposite of a good ice building pattern. The pattern is progressive so that storms will drop in and bring some cold, but it will not stick until we get towards the end of the month.

Here are 2 of the best forecast models 8-10-day averages for below / above normal temps.
You can see the eastern half of the county is predicted to be warm
BUT there are some big drivers of the atmosphere starting to point to a crash into winter by the end of the month. (As opposed to a slow step down to winter)
NAO is about to tank:
AO is about to tank:
So they will provide the setup for pushing Polar Arctic air from the north which is now building AHEAD of schedule due rapid growth in snowpack from below average to well above average over the extreme northern hemisphere.

The kingpin in all this is the Madden/Julian Oscillation (MJO) which is an indication of the position of tropical convection along the equator. The MJO will have a significant impact on weather patterns for North America this winter (more so then years prior)
Here is the latest observations (solid red line is Oct and blue is Nov) line) along with forecasted projections (Green and yellow) The number represent the position on that day of the month. (We are on Nov 7 in region 5)
When this moves into Region 8,1 and 2 this winter, look out. You can see thatís exactly where it was during the end of October, and itís about to repeat itself. Anytime itís over in regions 4, 5, 6 look for a ridge in the SE and warmth in the NE. When this goes into regions 8,1, and 2 while linking up with a Negative NAO/AO you can bet the NE is going to be middle a stormy and cold pattern.
All the above points a hard fast start to winter starting towards the end of Nov. Itís up the air whether this can setup fast enough to produce any meaningful ice by Thanksgiving. But if youíre thinking of hitting ice early and mid-December, things are lining up great!

11-09-2011, 06:42 AM
For those that like to track progress of the 3 key indicators for this winter season: (Again if we can get all three to come together just right, winter should arrive hard and fast, if not then we may see an up and down, but gradual decent into winter for the NE)

For NAO and AO patterns we want to see negative numbers. (Explanation of the two: http://www.nc-climate.ncsu.edu/climate/patterns/NAO.html)

Daily AO Observations and forecast: http://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/ao.shtml

Daily NAO Observations and forecast http://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/nao.shtml

For MJO we want to be in Regions 7,8,1 and the farther away from center the stronger the influence will be.

Daily MJO Observations and forecast: http://www.nynjpaweather.com/current-conditions/maddenjulian-oscillation/