[GraniteStater]

Pattern change is now eminent in the 6-10 day time frame for the East. The GFS computer model for multiple model runs in a row is building a ridge of a high pressure over the West and eastern Pacific. This correlates nicely with the PNA predicted to be in the positive range as it has just now flipped sign. This should lead to a pattern that supports more cold weather and snow chances for the Great Lakes and New England. So, in general, it means 4-5 days of average or below average temperatures and 2 days of above average temperatures when the new pattern sets up. I was getting concerned for awhile, but December might become a bit more favorable overall for cold & snow.

[GraniteStater]

The blowtorch pattern continues... Record highs are possible throughout northern New England over the next several days until a minor "front" moves through later next week. Like I mentioned, a pattern change will occur over the next 5-7 days, but it really is nothing that impressive. It will only send temperatures back to average. The PNA shifting into positive territory will allow for more high pressure ridging in the western US which should help cool things down in the east somewhat. However, the positive NAO and AO will not allow for much in the way of persistence of the cold airmass that does develop. Very much a La Nina pattern a reminiscient of the 99-00 event IMHO even though the current event is of weaker strength.

[Cambium]

Originally Posted by GraniteStater

The blowtorch pattern continues... Record highs are possible throughout northern New England over the next several days until a minor "front" moves through later next week. Like I mentioned, a pattern change will occur over the next 5-7 days, but it really is nothing that impressive. It will only send temperatures back to average. The PNA shifting into positive territory will allow for more high pressure ridging in the western US which should help cool things down in the east somewhat. However, the positive NAO and AO will not allow for much in the way of persistence of the cold airmass that does develop. Very much a La Nina pattern a reminiscient of the 99-00 event IMHO even though the current event is of weaker strength.

Yup..that should all change very shortly... Enjoy this weather while you can.

From NWS:
A TRUE ARCTIC BLAST BEGINS TO POUR DOWN FROM CANADA IN THE FORM OF A 1050 MB HIGH WHICH WILL MAKE FOR A COLD START TO THE MONTH OF DECEMBER.
http://forecast.weather.gov/product....n=1&glossary=1

[square peg]

I'm reading this with interest but not understanding some of the abbreviations, like: NAO, AO, and PNA. I'm good with IMHO and NWS, though.

[GraniteStater]

Originally Posted by square peg

I'm reading this with interest but not understanding some of the abbreviations, like: NAO, AO, and PNA. I'm good with IMHO and NWS, though.

Here is the site I use to check the forecasts:
CPC - Climate Weather Linkage: Teleconnections

NAO= North Atlantic Oscillation
AO= Arctic Oscillation
PNA= Pacific North American (pattern)

Basically, when the PNA is negative and the NAO and AO are positive (in their respective indicies) the East stays warmer than average. When the PNA is positive and the NAO and AO are negative the East stays colder than average. This is not always the case, but it often happens to correlate, particularly during the winter. Right now the PNA has flipped from negative to positive territory and a ridge of high pressure is forecasted to form in the Pacific in the medium range time period and then persist after that. So, one can assume a downstream trough will setup somewhere east of the Rockies.

[square peg]

Hey, thanks, GSer! My personal weather observations pretty much are cloud pattern related, which may be good for a day or two. This is good stuff!

[GraniteStater]

Model Analysis and Guidance: View parameters for selection


500mb thickness level loop on the 6Z GFS model run is starting to look more favorable for a more wintry temperature regime in New England in the medium range and later.

[Cambium]

Originally Posted by GraniteStater

Here is the site I use to check the forecasts:
CPC - Climate Weather Linkage: Teleconnections

NAO= North Atlantic Oscillation
AO= Arctic Oscillation
PNA= Pacific North American (pattern)

Basically, when the PNA is negative and the NAO and AO are positive (in their respective indicies) the East stays warmer than average. When the PNA is positive and the NAO and AO are negative the East stays colder than average. This is not always the case, but it often happens to correlate, particularly during the winter. Right now the PNA has flipped from negative to positive territory and a ridge of high pressure is forecasted to form in the Pacific in the medium range time period and then persist after that. So, one can assume a downstream trough will setup somewhere east of the Rockies.

Yes, thanks. Good post..beat me to it.

Here's a nice graph to illustrated what a phases of AO/NAO does... Notice in Negative phase the High pressures to the North and the cold air trapped below in the Eastern U.S.

[Cambium]

I was telling someone today as we complain about the bugs STILL around,.. that a few hour drive north of the coast and you guys still have a snowpack..

Other than that theres really no snowpack in the U.S aside from the Mountains out west. Wow.

[Cambium]

Here come the Global Warming comments... lol
Any record or extremes for Vermont lately?

"....CARIBOU,Maine IS EASILY ON TRACK TO HAVE ITS WARMEST
NOVEMBER ON RECORD. WITH LITTLE SNOW IN SIGHT...IT WILL ALSO BE
ONE OF THE SLOWEST STARTS TO THE SNOW SEASON FOR NORTHERN MAINE. CENTRAL/SOUTHERN MAINE HAS NOT BEEN QUITE SO SNOW STARVED AND WARM WITH RESPECT TO NORMAL THIS NOVEMBER."

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