Cold Start to December
Snowfall forecasting contests for 27 stations across New England and the Mid-Atlantic regions ... since 1999
Unless there/s been a big mistake in reporting the data...the AO took a steep...67% nose-dive today...as the index fell 1.456 points.
Yesterday/s AO index value had soared to 2.187.... creeping toward outlier territory.
Today...there must have been a strong 'sell' signal in the global teleconnection markets...b/c the index lost 2/3 of its value as it crashed-landed @ 0.730!
Positive AO values trend to keep Arctic air bottled up at hi-latitudes. When the AO lurks below zero...the cold air often escapes into the Lower 48.
By the looks of it...AO is heading downtown for an extended stay.
CPC/s latest 90-day outlook for NEWxSFC/s forecast area this coming meteorological winter (D-J-F) continues with its 'equal chances' theme from last month/s outlook.
Equal chances? Is that the best they can do?
In other words...the odds are 50 / 50. The same odds you have when flipping a fair coin. For this we pay how much?
Probability theory considers 50% as a 'good' chance of getting a desired outcome...so there/s no reason...yet...to abandon all hope for a memorable season.
The Climate Prediction Center...located in the World Weather Building...SE of Washington...DC...uses many tools to develop the 90-day outlook. CPC forecasters...or maybe they/re known as 'outlookers' inside the WWB...consider ENSO...climatological departures from persistence trends in 10-year temperature and 15-year precipitation periods...Madden-Julian Oscillation voodoo(MJO)...teleconnection indexes such as the North Atlantic Oscillation (NAO)...Pacific-North American (PNA)...and Pacific Decadal Oscillation (PDO)...along with current soil moisture anomalies...razz-ma-tazz statistical tools...and last but not least...the dynamic Climate Forecast System (CFS) model."The paper shows that the NAO and the AO have different impacts on winter NH (surafce air temperature) SAT. The variability of other atmospheric variables related to the AO and the NAO is discussed."A bit wonkish...but a still a good read.

Beautiful dendritic patterns over Italy/s Alps as observed last Sunday from space.
Note cloud cover to the north over Switzerland...Austria....France...and Germany.
Map

"Barrow at the northern tip of Alaska had 21″ of snow in 28 days (they average 29″ per year…it’s a cold desert up there).
"Fairbanks has only had two days warmer than average in the last month and a half. During October and early November, Fairbanks has been 8 degrees colder than average!
"On the southern coast, Anchorage has only had one month this year that has been warmer than average. They haven’t reached 30 degrees since Oct. 22 and the last three weeks have been five degrees colder than average.
"The water off Alaska is colder than average and the sun won’t be of any help until spring. That heavy, cold air will start building southward soon. The surface Arctic icecap grew this year and is now at its greatest areal extent since 2002."
"In a telephone interview yesterday from his New Hampshire home, Mr. D’Aleo said he is confident the rest of this month and December will be cold and potentially snowy. He said ice coverage in the Arctic has rebounded quickly and snow cover in that part of the world is at its usual depth for this time of year. He said that is important for this area, because air masses from the polar region head south toward Central Massachusetts in December.Ice coverage...
"“I suspect many of us will see snow on the ground before Thanksgiving,” he said.
"Mr. D’Aleo, however, also noted that he is less confident now than he was three weeks ago about a warm-up in January and February."
