CPC Outlook - Update - Winter '08 / '09

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.

ENSO is seen currently as neutral by CPC and it/s expected to remain that way throughout the upcoming winter...even though...NCEP/s own SST forecasts maintain slightly negative anomalies in Nino 3.4.

A much more detailed forecast discussion from the CPC is here.

AO and NAO - NHEMI Air Temperature Variability

Winter Northern Hemisphere surface air temperature variability
associated with the Arctic Oscillation and North Atlantic Oscillation

"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.

GEOPHYSICAL RESEARCH LETTERS, VOL. 32
Dongxiao Wang,1 Chunzai Wang,2 Xiaoyi Yang,1 and Jian Lu3
Published 20 August 2005.

AER - Winter Outlook '08 / '09

sCAST modeler Judah Cohen of AER expects 'warm' temperatures in the east this winter. Cohen mentions the below normal snow cover in Siberia as a contributing factor in this year/s forecast.

More...

Italy/s Alps

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

Coastal Teaser #1 - NOV '08

If this outlier scenario from today/s 12z GooFuS comes to pass toward week/s end...it would be the earliest contest storm ever.

Arctic Oscillation - October '08

CPC posted OCT/s Arctic Oscillation (AO) index recently and it/s up...WAY-T-F up.

OCT came in @ a monster +1.676...the 1st positive value since MAR '08.

It/s only one data point but an important one b/c stratospheric and tropospheric circulations tend to be coupled during winter.

The AO tends to be in its negative phase (weak...warm vortex) when the QBO is negative (easterly). A -AO favors arctic outbreaks over the eastern CONUS; whereas...+AO and QBO-W are associated with a strong...cold PV.

+AO is famous for hording the coldest air over hi-latitudes.
No cold...arctic air => weak baroclinicity.
Weak baroclinicity => less cyclogenesis.
Less cyclogenesis => fewer storms.
Fewer storms => less chance of snow from migratory cyclones.

Time to fold up the tents and go home?

There/s no doubt QBO will be positive (westerly) for most of the '08 / '09 winter...until @ least late FEB / early MAR...which suggests D-J-F...as a whole...might not-be-so-cold-'n-wintry after all.

Best AO analog years using a 'least-squares' method: '95 /'96...'73 / '74...'54 / '55...'75 / '76...and '72 / '73.



R² value is down-right putrid (0.385) for 1st-choice analog year and they go down hill from there. None of the 'best' AO years match up well with 'best' QBO years...so there/s little-to-no confidence the AO analogs offer much insight this go 'round.

Early Start - Winter '08 / '09

Good reason to think winter/s getting a head start this year. Ski resorts on both sides of the Atlantic Ocean are opening early. There have been encouraging events recently in the 49th state...as well.

"Mammoth Mountain in California and Bormio in Italy have both opened early for winter 2008-9." Mammoth opened 10 days early. Bormio a full month.

Breckenridge Ski Resort...CO. Earliest opening in 30 years.

"Baqueira Beret ski area in the Pyrenees will open a week earlier than planned, on Saturday November 22nd, rather than the 29th."

"Marmot Basin in Canada opens...Saturday 15th November, its earliest ever opening."

"Verbier has opened earlier than expected because of the heavy snowfall across the Alps in recent weeks."

Meanwhile...Bill Steffen...Chief Meteorologist @ WOOD-TV 8 in Grands Rapids...MI... blogs about recent events in Alaska...

"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."

D/Aleo Update - Winter Outlook '08 / '09

Speaking with the Worcester Telegram & Gazette News today...Joe D/Aleo refined his outlook a smidge for the coming winter...

"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.

"“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."

Ice coverage...


Latest monthly Nino3.4 outlook from CFS...

Almanac Outlooks - Winter '08 / '09

FWIW...

Eurasia Snow Cover - OCT '08 - Part II

October/s numbers for Eurasia areal snow cover are in and it ain/t pretty if you/re on the east coast and in the market for cold this winter.

Eurasia snow cover...Siberia specifically...is correlated negatively to east CONUS winter temperature in AER/s sCAST model...so as Eurasia snow cover goes...so goes sCAST.

Observed snow cover (L) Departures (R)

The Global Snow Lab @ Rutgers U. reports Eurasia areal snow cover for OCT @ 8.88 km² (25th percentile)...which is 13% below the period-of-record average (1967-2008) of 10.2 km². This compares to an -8% departure in NHEMI snow cover.


Eurasia/s OCT snow cover has been above average six (6) times during the past 10 years...most recently in 2006. Last year/s departure was -16%...which is not substantially different than this year. The '07 / '08 winter produced bonus snows across northern NE and disappointing totals elsewhere.



Snowfall departure analysis courtesy NCDC.

Other NEWxSFC posts about sCAST here.