The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or 
The CPC's 10 day to two week outlook. Their forecasts score a "2" out of their highest forecast confidence of "5":
"
Prognostic Discussions
Valid: Dec 24 - 28, 2012 (6-10 Day Outlook)
Valid: Dec 26 - Jan 01, 2012-13 (8-14 Day Outlook)
Issued: Dec 18, 2012
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PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EST TUE DECEMBER 18 2012
6-10 DAY OUTLOOK FOR DEC 24 - 28 2012
SEVERAL KEY UNCERTAINTIES REMAIN AS TO THE EVOLUTION OF A POTENTIALLY
HIGH-IMPACT STORM SYSTEM OVER THE THE EASTERN TWO THIRDS OF THE CONUS.
CONFIDENCE REMAINS FAIRLY HIGH IN THE OVERALL LONGWAVE STRUCTURE DISCUSSED
YESTERDAY: A SLOWLY WEAKENING BLOCK CENTERED OVER THE NORTHERN PART OF THE
CONTINENT, A TROUGH NEAR THE WEST COAST, AND A TROUGH OFF THE EAST COAST. THE
ENSEMBLE MEANS ARE IN GOOD AGREEMENT ON THESE KEY FEATURES. IN TODAY'S MANUAL
BLEND, A BLOCK OVER NORTHERN CANADA IS MORE EVIDENT THAN FROM YESTERDAY'S
FORECAST, AS THE MODEL SOLUTIONS ARE IN BETTER AGREEMENT THAT HEIGHT RISES OVER
ALASKA BEFORE THE PERIOD WILL CUT OFF NORTH OF THE MEAN FLOW, WHICH WILL IN
TURN PUSH COLDER AIR SOUTH TOWARD THE CONUS. HOWEVER, RECENT MODEL PERFORMANCE
PRECLUDES A HIGH-CONFIDENCE OUTLOOK.
SUPERIMPOSED ON THE POOR MODEL PERFORMANCE IS THE CONFOUNDING ISSUE OF A
POTENTIAL PATTERN CHANGE. THIS PATTERN CHANGE MIGHT BE SUBTLE IN TERMS OF
CHANGES TO SOME OF THE DOMINANT TELECONNECTIONS. THE PNA, NAO, AND AO ARE NOT
CURRENTLY FORECAST TO HAVE MAJOR SIGN CHANGES OVER THE NEXT COUPLE OF WEEKS.
HOWEVER, THE POSITION OF THE ANOMALIES THAT GIVES RISE TO THE OBSERVED VALUES
MAY BE SHIFTING, WITH HIGHER HEIGHTS DEVELOPING IN NORTHERN NORTH AMERICA. THE
OBSERVED POSITIVE HEIGHT ANOMALIES SOUTH OF THE ALEUTIANS ARE FORECAST TO
WEAKEN CONSIDERABLY, WHILE STRONGER POSITIVE HEIGHT ANOMALIES ARE MORE LIKELY
TO DOMINATE FROM NEAR HUDSON BAY TO THE POLE.
ABOVE NORMAL TEMPERATURES ARE FAVORED ACROSS THE NORTHERN GREAT LAKES WHERE
ARCTIC AIR IS SLOW TO BUILD EARLY IN THE PERIOD AND IS THEN MODIFIED BY
EASTERLY FLOW AHEAD OF A POTENTIAL STORM SYSTEM LATER IN THE PERIOD. TODAY'S
OUTLOOK IS SIMILAR TO THE ONE ISSUED YESTERDAY ACROSS THE NORTHWEST AND
NORTHERN ROCKIES. COLDER THAN NORMAL TEMPERATURES ARE FAVORED FARTHER SOUTH
AND EAST AS AN ARCTIC HIGH CONTINUES TO PUSH SOUTH FROM CANADA. ABOVE NORMAL
TEMPERATURES EARLY IN THE PERIOD IN THE SOUTH-CENTRAL AND SOUTHEASTERN CONUS
SHOULD BE BALANCED BY COLDER AIR BEHIND ANY STORM SYSTEM LATER, ALTHOUGH WITH
HIGH UNCERTAINTY. THE LARGEST WEATHER-MAKER DURING THE PERIOD IS LIKELY TO BE A WINTER STORM THAT
OCCURS FROM THE CENTRAL CONUS EASTWARD. THE TRACK AND STRENGTH OF THIS SYSTEM
REMAINS VERY UNCERTAIN. AN ACTIVE STORM TRACK FROM CENTRAL CALIFORNIA THROUGH
THE MIDDLE OF THE COUNTRY STILL SEEMS PROBABLE, ENHANCING PROBABILITIES OF
ABOVE-MEDIAN PRECIPITATION ACROSS MOST OF THE CONUS. SOME UPSLOPING ON THE
SOUTHERN SIDE OF A BUILDING HIGH PRESSURE SYSTEM INCREASES ODDS OF ABOVE-MEDIAN
PRECIPITATION OVER THE NORTHERN ROCKIES. THE ONLY AREA WHERE DRIER-THAN-MEDIAN
CONDITIONS ARE FAVORED IS ACROSS WEST TEXAS, WHICH SHOULD REMAIN JUST SOUTH OF
AN ACTIVE STORM TRACK.
TODAY'S OFFICIAL 500-HPA BLEND CONSISTS OF 15 PERCENT OF TODAY'S OPERATIONAL 0Z GFS CENTERED ON DAY 8...15 PERCENT OF TODAY'S OPERATIONAL 6Z GFS CENTERED ON
DAY 8...10 PERCENT OF TODAY'S 0Z GFS ENSEMBLE MEAN CENTERED ON DAY 8...20
PERCENT OF TODAY'S 6Z GFS ENSEMBLE MEAN CENTERED ON DAY 8...20 PERCENT OF
TODAY'S OPERATIONAL 0Z ECMWF CENTERED ON DAY 8...AND 20 PERCENT OF TODAY'S 0Z
EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 8.
MODEL OF THE DAY: TODAY'S 00Z ECMWF ENSEMBLE MEAN
FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: BELOW AVERAGE, 2 OUT OF 5, DUE TO
GOOD AGREEMENT AMONG ENSEMBLE MEANS OFFSET BY HIGH UNCERTAINTY ASSOCIATED WITH
A SUPPRESSED ZONAL FLOW AND THE FATE OF THE STORM TRACK SOUTH OF POSITIVE
HEIGHT ANOMALIES IN NORTHEASTERN CANADA.
8-14 DAY OUTLOOK FOR DEC 26, 2012 - JAN 01, 2013
THE GFS AND ECMWF ENSEMBLE MEANS REMAIN IN REASONABLY GOOD AGREEMENT ON THE
LONGWAVE PATTERN, WHICH IS SIMILAR TO THE 6-10 PERIOD. THE ECMWF ENSEMBLE
MEMBERS CONTINUE TO EXHIBIT LOW SPREAD IN AGREEING UPON BELOW NORMAL 500-HPA
HEIGHTS ACROSS THE CONUS. HIGH-LATITUDE, POSITIVE HEIGHT ANOMALIES OVER NORTH
AMERICA SEEM TO BE THE DOMINANT FEATURE, TELECONNECTING TO SLIGHTLY LOWER THAN
NORMAL HEIGHTS OVER MOST OF THE CONUS.
AN ACTIVE STORM TRACK ACROSS THE CONUS APPEARS TO BE A CHARACTERISTIC FEATURE
OF THIS PERIOD. AS SUCH, ABOVE-MEDIAN PRECIPITATION PROBABILITIES REMAIN HIGH
OVER MOST OF THE CONUS, WITH VERY LITTLE CHANGE FROM YESTERDAY'S FORECAST. THE
TEMPERATURE FORECAST REMAINS UNCERTAIN EAST OF THE MISSISSIPPI RIVER, AS IT
DEPENDS ON TWO KEY DEVELOPMENTS: THE STRENGTH OF ARCTIC HIGH PRESSURE FORECAST
TO PUSH INTO THE PLAINS AND NORTHERN ROCKIES, AND THE PATH OF AT LEAST ONE
(POSSIBLY TWO) SIGNIFICANT STORM SYSTEM. THE FORECAST IN THE EAST STILL FAVORS
A BALANCE BETWEEN SLIGHTLY MILDER TEMPERATURES EARLY, FOLLOWED BY COLDER
TEMPERATURES LATER. BELOW NORMAL TEMPERATURES ARE FAVORED FROM THE NORTHERN
ROCKIES TO THE CENTRAL CONUS AND ALONG THE WEST COAST WHERE UPPER-LEVEL HEIGHTS
ARE EXPECTED TO REMAIN SIGNIFICANTLY BELOW NORMAL AND ARCTIC HIGH PRESSURE FROM
THE NORTH BECOMES AN IMPORTANT FACTOR. THE QUESTION POSED YESTERDAY OF WHETHER POSITIVE HEIGHT ANOMALIES PERSISTENTLY
BUILD OVER ALASKA DURING THE PERIOD IS HEADED TOWARD A SOLUTION. THE GFS
ENSEMBLES HAVE BEEN HINTING AT THIS FOR A COUPLE OF DAYS AND THE ECMWF
ENSEMBLES ARE HEADING IN THAT DIRECTION. WARMER THAN NORMAL TEMPERATURES ARE
FAVORED OVER THE WESTERN PART OF ALASKA IN RESPONSE TO THIS. SHOULD HEIGHTS
RISE OVER ALASKA, THAT COULD POINT TOWARD A DISCHARGE OF ARCTIC AIR TOWARD THE
CONUS, FIRST IN THE NORTHERN ROCKIES. THIS SEEMS MORE LIKELY THAN IT DID
YESTERDAY AND THE WESTERN TWO THIRDS OF THE CONUS WOULD BE IMPACTED FIRST.
THE OFFICIAL 8-14 DAY HEIGHT PROG CONSISTS OF: 15 PERCENT OF TODAY'S 0Z GFS
ENSEMBLE MEAN CENTERED ON DAY 11...20 PERCENT OF TODAY'S 6Z GFS ENSEMBLE MEAN
CENTERED ON DAY 11...50 PERCENT OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN CENTERED
ON DAY 11...AND 15 PERCENT OF TODAY'S 0Z CANADIAN ENSEMBLE MEAN CENTERED ON DAY
11.
FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD IS: BELOW AVERAGE, 2 OUT OF 5, DUE
TO HIGH UNCERTAINTY ASSOCIATED WITH A SUPPRESSED ZONAL FLOW, SOME LARGE
DISAGREEMENT BETWEEN FORECAST TOOLS, AND PERSISTENTLY POOR MODEL PERFORMANCE.
FORECASTER: STEPHEN BAXTER
"
. Maybe hyping this up a week early wasn't such a good idea for the sensitive folks 
. Last winter we couldn't even buy two days worth of it!
