PROGNOSTIC DISCUSSIONS FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS NWS CLIMATE PREDICTION CENTER CAMP SPRINGS MD 300 PM EST WED JAN 02 2008 6-10 DAY OUTLOOK VALID FOR JAN 08 - 12 2008 TODAYS MODEL GUIDANCE IS IN FAIRLY GOOD AGREEMENT ON THE AVERAGE 500-HPA CIRCULATION PATTERN EXPECTED FOR THE 6 TO 10 DAY PERIOD. THE DIFFERENCES BETWEEN MODELS CONTINUES TO FOCUS LARGELY ON THE INTENSITY OF LONG WAVES RATHER THAN THEIR POSITIONING ACROSS THE VICINITY OF NORTH AMERICA. MOST MODEL SOLUTIONS PREDICT A TROUGH ACCOMPANIED BY BELOW NORMAL 500-HPA HEIGHTS FROM SIBERIA AND ALASKA SOUTHEASTWARD ACROSS WESTERN CANADA AND THE WESTERN CONUS, AND ANOTHER TROUGH CENTERED BETWEEN ICELAND AND THE BRITISH ISLES IN THE FAR NORTHEASTERN ATLANTIC. THERE ARE NOW CONSIDERABLE VARIATIONS PREDICTED IN BOTH THE STRENGTH AND LOCATION OF THE GREATEST HEIGHT ANOMALY ASSOCIATED WITH THE NORTH PACIFIC RIDGE WHICH HAS BEEN PREDICTED BY MODELS NEAR 35N-40N/160W-165W FOR THE PAST SEVERAL DAYS. THE OPERATIONAL 0Z GFS, 6Z GFS, AND 0Z ECMWF ALL HINT AT A MAXIMUM POSITIVE HEIGHT ANOMALY MUCH CLOSER TO THE U.S. WEST COAST. ONLY THE 0Z GFS INDICATES A CLEAR BREAK IN THE FULL LATITUDE WEST COAST TROUGH, CENTERED OVER SOUTHWEST CANADA AND THE PACIFIC NORTHWEST. MEANWHILE, THE UNUSUALLY STRONG RIDGE WHICH MODELS HAVE BEEN ANTICIPATING NEAR THE SOUTHERN CANADIAN MARITIMES AND NORTHERN NEW ENGLAND FOR THE PAST FEW DAYS IS ALSO SHOWING SIGNS OF RESTRUCTURING FURTHER TO THE NORTHWEST ...NEAR NORTHERN HUDSON BAY. THIS WILL ALLOW FOR THE GENERATION OF VERY COLD CONTINENTAL AIR MASSES WHICH COULD PLUNGE SOUTHWARD INTO THE CENTRAL AND EASTERN CONUS DURING THE WEEK 2 PERIOD, AND THUS BEARS WATCHING. THE CORRELATION BETWEEN TODAYS OFFICIAL BLEND AND THE COMPOSITE HEIGHT ANALOG (AVERAGE OF 10 BEST HISTORICAL ANALOGS) IS 0.925 WHICH IS QUITE HIGH. FOR THE MOST PART, A WARM AND WET PATTERN IS FORECAST FOR MUCH OF THE CONUS DURING THIS PERIOD, WHILE COLD AND DRY CONDITIONS PREVAIL OVER ALASKA. TODAYS OFFICIAL 500-HPA BLEND CONSISTS OF 10 PERCENT OF TODAY'S OPERATIONAL 0Z GFS CENTERED ON DAY 8...10 PERCENT OF TODAY'S OPERATIONAL 6Z GFS CENTERED ON DAY 8...15 PERCENT OF TODAY'S OPERATIONAL ECMWF CENTERED ON DAY 7...20 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...10 PERCENT OF TODAY'S CANADIAN ENSEMBLE MEAN CENTERED ON DAY 8...AND 15 PERCENT OF TODAY'S EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 7. MODEL(S) OF THE DAY: 0Z AND 6Z GFS ENSEMBLE MEANS FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD IS NEAR AVERAGE... 3 ON A SCALE OF 1 TO 5... DUE TO FAIRLY GOOD MODEL AGREEMENT BUT OFFSET BY UNCERTAINTIES IN THE STRENGTH AND LOCATION OF BOTH RIDGES NOTED ABOVE IN THE DISCUSSION. THE 6-10 DAY TEMPERATURE PROG IS BASED ON THE THE CPC AUTO FORECAST... THE NORTH AMERICAN ENSEMBLE FORECAST SYSTEM TEMPERATURE GUIDANCE... KLEIN - NEURAL NET - AND ANALOG SPECIFICATIONS FROM THE OFFICIAL BLEND... AND CDC REFORECAST TEMPERATURES. THE 6-10 DAY PRECIPITATION PROG IS BASED ON THE CPC AUTO FORECAST... THE CDC REFORECAST... AND NEURAL NETWORK AND ANALOG SPECIFICATIONS FROM THE OFFICIAL BLEND. 8-14 DAY OUTLOOK FOR JAN 10 - 16 2008: THE ATMOSPHERIC CIRCULATION FOR THE WEEK 2 FORECAST PERIOD IS EXPECTED TO UNDERGO RAPID CHANGES COMPARED TO THE 6-10 DAY FORECAST PATTERN. AS A RESULT, SIGNIFICANT DIFFERENCES ARE APPARENT BETWEEN MODEL SOLUTIONS. THE CANADIAN ENSEMBLE MEAN HOLDS ON TO A PATTERN WHICH IS SIMILAR TO THAT PREDICTED FOR DAYS 6-10, BUT THE OTHER MODEL SOLUTIONS DIFFER IN SEVERAL WAYS. FOR EXAMPLE, THERE IS A NOTICEABLE SPLIT IN THE BROAD WEST COAST TROUGH, WITH A CONCENTRATION OF BELOW NORMAL 500-HPA HEIGHTS OVER WESTERN ALASKA AND THE BERING SEA, AND ANOTHER CONCENTRATION OF BELOW NORMAL HEIGHTS OVER THE SOUTHWESTERN CONUS. THERE IS ALSO A MODERATE RIDGE FORECAST OVER THE EASTERN GULF OF ALASKA AND INTO WESTERN CANADA. THERE IS SOME INDECISION ON THE PART OF MOST MODELS AS TO WHERE TO PLACE THE UNUSUALLY STRONG RIDGE OVER THE SOUTHERN MARITIMES REGION IN THE PRECEDING 6-10 DAY PERIOD. IF THE RIDGE REMAINS IN THIS SAME LOCATION, THE EASTERN CONUS WOULD STAY RELATIVELY WARM, BUT IF, AS SOME MODEL RUNS SHOW, THIS RIDGE RELOCATES TO NORTHERN HUDSON BAY, VERY COLD CONTINENTAL AIR MASSES WOULD BE GENERATED. SOON THEREAFTER, ARCTIC AIR MAY STREAM SOUTHWARD ACROSS THE BORDER INTO THE CENTRAL (AND POSSIBLY EASTERN) CONUS. HOPEFULLY, TOMORROWS MODEL RUNS WILL ALLOW US TO BETTER ASSESS THE LIKELIHOOD OF THIS POSSIBILITY. THE OFFICIAL 8-14 DAY HEIGHT PROG CONSISTS OF 15 PERCENT OF TODAY'S OPERATIONAL 6Z GFS CENTERED ON DAY 11...40 PERCENT OF TODAY'S 0Z GFS ENSEMBLE MEAN CENTERED ON DAY 11...35 PERCENT OF TODAY'S 6Z GFS ENSEMBLE MEAN CENTERED ON DAY 11...AND 10 PERCENT OF TODAY'S CANADIAN ENSEMBLE MEAN CENTERED ON DAY 11. FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD IS BELOW AVERAGE... 2 ON A SCALE OF 1 TO 5... DUE PRIMARILY TO THE EXPECTATION OF A RAPIDLY EVOLVING PATTERN FROM DAYS 6-10. THE 8-14 DAY TEMPERATURE PROG IS BASED ON THE CPC AUTO FORECAST... THE CDC REFORECAST... KLEIN - NEURAL NETWORK - AND ANALOG SPECIFICATIONS FROM THE BLEND... AND THE NORTH AMERICAN ENSEMBLE FORECAST SYSTEM TEMPERATURE GUIDANCE. THE 8-14 DAY PRECIPITATION PROG IS BASED ON THE CPC AUTO FORECAST... THE CDC REFORECAST... NEURAL NET AND ANALOG SPECIFICATIONS FROM THE OFFICIAL BLEND... AND THE CPC CALIBRATED PRECIPITATION PERCENTAGES FROM THE GFS ENSEMBLE MEMBERS. FORECASTER: A. ARTUSA NOTES: OPERATIONAL CHANGE: AS OF JULY 5 2005 SHADED MAPS HAVE REPLACED THE CONTOUR-ONLY MAPS ON THE CPC WEB SITE. THE CONTOURED MAPS ARE STILL AVAILABLE AT THEIR CURRENT FILE NAMES - SO DIRECT-LINKED USERS ARE NOT AFFECTED. AWIPS GRAPHICS ARE ALSO NOT AFFECTED BY THIS CHANGE. AUTOMATED FORECASTS ARE ISSUED ON SATURDAY AND SUNDAY. OTHERWISE - FORECASTS INCORPORATE FORECASTER INPUT. THE NOTATION FOR THE CATEGORICAL FORECAST INDICATED ON THE MAPS IS THE SAME AS THAT IN THE TABLES: A-ABOVE N-NEAR NORMAL B-BELOW IN THE SOUTHWEST AND OTHER CLIMATOLOGICALLY DRY REGIONS - THERE WILL BE A GREATER THAN 33.3% CHANCE OF NO PRECIPITATION AND OCCASIONALLY EVEN A NORMAL (I.E. MEDIAN) VALUE OF ZERO - ESPECIALLY DURING THE DRY SEASONS. IN SUCH CASES A FORECAST OF NEAR NORMAL IS EFFECTIVELY A FORECAST OF LITTLE OR NO PRECIPITATION. THE NARRATIVE DESCRIPTION OF THE FORECAST PATTERNS FOR TEMPERATURE AND PRECIPITATION FOR BOTH THE 6-10 OR 8-14 DAY PERIODS HAS BEEN DISCONTINUED. THE STATE TABLES FOR BOTH THE 6-10 AND 8-14 DAY PERIODS ARE NOW CONTAINED IN THIS MESSAGE...AVAILABLE AS PMDMRD ON AWIPS. THE CLIMATE PREDICTION CENTER USES 1971-2000 BASE PERIOD MEANS FOR TEMPERATURE...PRECIPITATION...AND 500-HPA HEIGHTS AS REFERENCE IN THE CLIMATE OUTLOOKS. THE NEXT SET OF LONG-LEAD MONTHLY AND SEASONAL OUTLOOKS WILL BE RELEASED ON JANUARY 18. NEW NOTE EFFECTIVE MAR 16 2004: THE GLOSSARY FORMERLY FOUND AT THIS LOCATION WILL NO LONGER BE TRANSMITTED AS PART OF THIS MESSAGE. IF YOU WISH TO SEE THE DEFINITIONS OF TERMS USED IN THESE MESSAGES... PLEASE GO TO THE CPC WEB PAGE AT (USE LOWER CASE) HTTP://WWW.CPC.NCEP.NOAA.GOV AND FOLLOW THE APPROPRIATE LINKS. ANALOGS TO THE 5 DAY MEAN OBSERVED PATTERN CENTERED 3 DAYS AGO (D-3) FOR THE REGION FROM 20N to 70N LATITUDE AND 175E to 60W LONGITUDE INCLUDE THE 5 DAY PERIODS CENTERED ON THE FOLLOWING DATES: 19571219 - 19731228 - 19760109 - 19890110 - 19990116 ANALOGS TO THE 7 DAY MEAN OBSERVED PATTERN CENTERED 4 DAYS AGO (D-4) FOR THE REGION FROM 20N to 70N LATITUDE AND 175E to 60W LONGITUDE INCLUDE THE 5 DAY PERIODS CENTERED ON THE FOLLOWING DATES: 19890110 - 19571219 - 19731228 - 19640108 - 19760109 6 to 10 day Outlook Table OUTLOOK FOR JAN 08 - 12, 2008 STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN WASHINGTON N A OREGON B A NRN CALIF B A SRN CALIF B A IDAHO N A NEVADA B A W MONTANA N A E MONTANA A B WYOMING A A UTAH N A ARIZONA B A COLORADO N A NEW MEXICO N A N DAKOTA A N S DAKOTA A A NEBRASKA A A KANSAS A A OKLAHOMA A A N TEXAS A N S TEXAS A B W TEXAS A A MINNESOTA A A IOWA A A MISSOURI A A ARKANSAS A A LOUISIANA A N WISCONSIN A A ILLINOIS A A MISSISSIPPI A N MICHIGAN A A INDIANA A A OHIO A A KENTUCKY A A TENNESSEE A A ALABAMA A N NEW YORK A A VERMONT A A NEW HAMP A A MAINE A A MASS A A CONN A A RHODE IS A A PENN A A NEW JERSEY A A W VIRGINIA A A MARYLAND A A DELAWARE A N VIRGINIA A N N CAROLINA A N S CAROLINA A N GEORGIA A N FL PNHDL A B FL PENIN A B AK N SLOPE B B AK ALEUTIAN B B AK WESTERN B B AK INT BSN B B AK S INT B B AK SO COAST B B AK PNHDL B N 8 to 14 day Outlook Table OUTLOOK FOR JAN 10 - 16, 2008 STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN WASHINGTON A B OREGON N B NRN CALIF B B SRN CALIF B N IDAHO N B NEVADA B N W MONTANA N B E MONTANA N B WYOMING N N UTAH B N ARIZONA B N COLORADO N N NEW MEXICO B A N DAKOTA N N S DAKOTA N N NEBRASKA N N KANSAS N A OKLAHOMA N A N TEXAS N A S TEXAS N N W TEXAS N A MINNESOTA A N IOWA A A MISSOURI A A ARKANSAS A A LOUISIANA A N WISCONSIN A N ILLINOIS A A MISSISSIPPI A A MICHIGAN A N INDIANA A A OHIO A A KENTUCKY A A TENNESSEE A A ALABAMA A N NEW YORK A N VERMONT A N NEW HAMP A N MAINE A N MASS A N CONN A N RHODE IS A N PENN A N NEW JERSEY A N W VIRGINIA A N MARYLAND A N DELAWARE A N VIRGINIA A N N CAROLINA A N S CAROLINA A N GEORGIA A N FL PNHDL A B FL PENIN A B AK N SLOPE B N AK ALEUTIAN B A AK WESTERN B A AK INT BSN N A AK S INT N A AK SO COAST N A AK PNHDL A N LEGEND TEMPS WITH RESPECT TO NORMAL PCPN WITH RESPECT TO MEDIAN A - ABOVE N - NEAR NORMAL A - ABOVE N - NEAR MEDIAN B - BELOW B - BELOW THE FORECAST CLASSES REPRESENT AVERAGES FOR EACH STATE. NORMAL VALUES - WHICH MAY VARY WIDELY ACROSS SOME STATES - ARE AVAILABLE FROM YOUR LOCAL WEATHER SERVICE FORECAST OFFICE. FOR ADDITIONAL INFORMATION SEE MESSAGE FXUS06 KWBC - ON AWIPS AS PMDMRD. $$