PROGNOSTIC DISCUSSIONS FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS NWS CLIMATE PREDICTION CENTER CAMP SPRINGS MD 300 PM EDT MON OCT 11 2004 6 TO 10 DAY OUTLOOK FOR OCTOBER 17 - OCTOBER 21 2004 . . . . . . . DURING THE 6-10 DAY PERIOD THE MODELS FORECAST A DEAMPLIFICATION OF THE OVERALL CIRCULATION PATTERN FROM THAT FORECAST FOR DAYS 1-5. A BROADLY CYCLONIC FLOW IS FORECAST ACROSS MOST OF THE CONUS WITH A HANG-BACK TROUGH EXTENDING SOUTHWESTWARD INTO THE EASTERN PACIFIC OFF THE CALIFORNIA COAST. HEIGHTS ARE FORECAST TO BE BELOW NORMAL ACROSS MOST OF THE CONUS...EXCEPT OVER THE EXTREME NORTHEASTERN PART OF NEW ENGLAND AND OVER THE SOUTHWEST U.S. THE OPERATIONAL ECMWF IS A BIT SLOWER TO LOWER HEIGHTS OVER THE EASTERN U.S. COMPARED TO THE OTHER MODEL SOLUTIONS. THE BROADLY CYCLONIC FLOW SHOULD BRING COOL AND WET CONDITIONS TO MUCH OF THE NORTHERN TIER OF STATES. THE MODELS TODAY ARE A LITTLE LESS PROGRESSIVE WITH THE MAIN CIRCULATION FEATURES COMPARED TO YESTERDAY BUT OTHERWISE SHOW GOOD CONTINUITY. THE ENSEMBLE SPAGHETTI DIAGRAMS INDICATE RELATIVELY LITTLE SPREAD TODAY EXCEPT ALONG THE WEST COAST AND OVER THE EASTERN PACIFIC...MAINLY IN REGARD TO THE POSITION OF THE TROUGH FORECAST WEST OF THE CALIFORNIA COAST. THE PNA INDEX WHICH RECENTLY HAS TRENDED WEAKLY POSITIVE IS FORECAST BY THE GFS ENSEMBLE MEAN TO BECOME NEGATIVE BY DAY 7 AND REMAIN NEGATIVE THROUGH DAY 10 AND THEN TREND TOWARDS ZERO BY THE END OF THE WEEK 2 PERIOD. THE NAO INDEX WHICH RECENTLY HAS BEEN NEGATIVE IS FORECAST TO REMAIN NEGATIVE THROUGH THE NEXT TWO WEEKS. BOTH INDICES SHOW A LARGE AMOUNT OF SPREAD AMONG THE INDIVIDUAL ENSEMBLE MEMBERS SO CONFIDENCE IS LOW WITH RESPECT TO THE FORECAST OF THE PHASE OF THE PNA AND NAO. THE OFFICIAL D+8 HEIGHT PROG CONSISTS OF 20 PERCENT OF TODAYS GFS ENSEMBLE MEAN CENTERED ON DAY 8... 25 PERCENT OF THE MOST RECENT ECMWF ENSEMBLE MEAN CENTERED ON DAY 7... 15 PERCENT OF THE OPERATIONAL ECMWF CENTERED ON DAY 7... 10 PERCENT EACH OF TODAYS 0Z AND 6Z GFS CENTERED ON DAY 8... 15 PERCENT OF TODAYS CANADIAN ENSEMBLE MEAN CENTERED ON DAY 8 AND 5 PERCENT OF TODAYS DAVA CENTERED ON DAY 8. MODEL OF THE DAY: ECMWF ENSEMBLE MEAN FORECAST CONFIDENCE FOR THE 6 TO 10 DAY PERIOD IS ABOVE AVERAGE TODAY...4 ON A SCALE FROM 1 TO 5. THE 6 TO 10 DAY TEMPERATURE PROG IS BASED ON THE KLEIN AND ANALOG SPECIFICATIONS FROM THE OFFICIAL 500-HPA BLEND... THE CDC CALIBRATED TEMPERATURE FORECAST AND THE BIAS CORRECTED 0Z GFS 850-HPA TEMPERATURE FORECAST. THE 6 TO 10 DAY PRECIPITATION PROG IS BASED ON CALIBRATED PRECIP- ITATION PERCENTAGES FROM THE GFS ENSEMBLE MEMBERS...THE NEURAL NET AND ANALOG PRECIPITATION SPECIFICATIONS FROM THE 500-HPA BLEND... BIAS CORRECTED PRECIPITATION FROM THE GFS ENSEMBLE MEAN AND THE CDC CALIBRATED PRECIPITATION FORECAST. . . . . . . . 8 TO 14 DAY OUTLOOK FOR OCTOBER 19 - OCTOBER 25 2004 DURING WEEK 2 THE GFS ENSEMBLE MEAN FORECASTS LITTLE CHANGE TO THE OVERALL CIRCULATION PATTERN FROM THAT FORECAST FOR THE 6-10 DAY PERIOD. HEIGHTS ARE FORECAST TO RISE OVER THE EASTERN U.S. BUT MOST OF THE CONUS CONTINUES TO BE FORECAST TO BE DOMINATED BY A BROAD CYCLONIC FLOW. THE 6Z GFS IS THE MOST AMPLIFIED WITH THE FORECAST PATTERN AS IT BUILDS A RIDGE IN THE EAST AND PHASES THE NORTHERN AND SOUTHERN JET STREAMS IN THE WEST...THUS DEEPENING A TROUGH ALONG THE WEST COAST. THE DAVA IS SIMILAR TO THE GFS ENSEMBLE MEAN EXCEPT IT IS QUICKER TO RAISE HEIGHTS IN WESTERN CANADA. THE TROUGH FORECAST IN THE WEST SHOULD LEAD TO BELOW NORMAL TEMPERATURES AND ABOVE NORMAL PRECIPITATION OVER MUCH OF THE WESTERN U.S. WHILE THE BUILDING RIDGE IN THE EAST SHOULD LEAD TO ABOVE NORMAL TEMPERATURES AND BELOW NORMAL PRECIPITATION OVER THE EASTERN THIRD OF THE CONUS. THE MODELS SHOW GOOD CONTINUITY WITH RESPECT TO THEIR SOLUTIONS FROM YESTERDAY...THOUGH THE 6Z GFS IS A BIT LESS PROGRESSIVE TODAY COMPARED TO ITS PREVIOUS FORECAST. THE GFS ENSEMBLE SPAGHETI DIAGRAMS INDICATE A MODERATE AMOUNT OF SPREAD TODAY...ESPECIALLY OVER THE EAST PACIFIC AND ALONG THE NORTHERN TIER STATES. THE OFFICIAL 8-14 DAY HEIGHT PROG CONSISTS OF 50 PERCENT OF TODAYS GFS ENSEMBLE MEAN CENTERED ON DAY 11... 15 PERCENT OF TODAYS 0Z GFS CENTERED ON DAY 11... 25 PERCENT OF TODAYS 6Z GFS CENTERED ON DAY 11 AND 10 PERCENT OF TODAYS DAVA CENTERED ON DAY 11. FORECAST CONFIDENCE FOR THE 8 TO 14 DAY PERIOD IS ABOVE AVERAGE TODAY... 4 ON A SCALE OF 1 TO 5. THE 8 TO 14 DAY TEMPERATURE PROG IS BASED ON THE KLEIN... ANALOG AND NEURAL NET SPECIFICATIONS FROM THE OFFICIAL 500-HPA BLEND... THE CDC CALIBRATED TEMPERATURE FORECAST AND THE BIAS CORRECTED 0Z GFS 850-HPA TEMPERATURE FORECAST. THE 8 TO 14 DAY PRECIPITATION PROG IS BASED ON ANALOG AND NEURAL NET SPECIFICATIONS FROM THE OFFICIAL 500-HPA PROG...CALIBRATED PRECIP- ITATION PERCENTAGES FROM THE GFS ENSEMBLE MEMBERS... BIAS CORRECTED PRECIPITATION FROM THE 0Z OPERATIONAL GFS AND GFS ENSEMBLE MEAN AND THE CDC CALIBRATED PRECIPITATIN FORECAST. FORECASTER: R. SCHECHTER . . . . . . . NOTES: 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. EFFECTIVE THURSDAY MAY 17 2001...THE CLIMATE PREDICTION CENTER HAS SWITCHED TO 1971-2000 BASE PERIOD MEANS FOR TEMPERATURE... PRECIPITATION...AND 500-HPA HEIGHTS AS REFERENCE IN THE CLIMATE OUTLOOKS. THE 1971-2000 BASE PERIOD MEANS HAVE REPLACED THE 1961-1990 BASE PERIOD MEANS. THE NEXT MONTHLY AND SEASONAL OUTLOOKS WILL BE RELEASED THURSDAY... OCTOBER 21. 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: 19631020 - 19631023 - 19841009 - 19831020 - 19651018 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 7 DAY PERIODS CENTERED ON THE FOLLOWING DATES: 19631021 - 19631024 - 19790927 - 19561016 - 19841009 6 to 10 day Outlook Table OUTLOOK FOR OCT 17 - 21, 2004 STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN WASHINGTON B A OREGON B A NRN CALIF N A SRN CALIF N A IDAHO B A NEVADA N A W MONTANA B A E MONTANA B A WYOMING N A UTAH N N ARIZONA A N COLORADO A B NEW MEXICO A B N DAKOTA B A S DAKOTA N A NEBRASKA N N KANSAS A B OKLAHOMA A B N TEXAS A B S TEXAS A B W TEXAS A B MINNESOTA B A IOWA N A MISSOURI N N ARKANSAS A N LOUISIANA A N WISCONSIN B A ILLINOIS B A MISSISSIPPI A N MICHIGAN B A INDIANA B A OHIO B A KENTUCKY B A TENNESSEE B N ALABAMA N N NEW YORK B A VERMONT N A NEW HAMP N A MAINE A A MASS A A CONN N A RHODE IS N A PENN B N NEW JERSEY B N W VIRGINIA B N MARYLAND B N DELAWARE B N VIRGINIA B N N CAROLINA B N S CAROLINA B N GEORGIA N N FL PNHDL N N FL PENIN N B AK N SLOPE A A AK ALEUTIAN A N AK WESTERN A A AK INT BSN N A AK S INT N B AK SO COAST B B AK PNHDL B B 8 to 14 day Outlook Table OUTLOOK FOR OCT 19 - 25, 2004 STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN WASHINGTON B A OREGON B A NRN CALIF B A SRN CALIF B N IDAHO B A NEVADA B A W MONTANA B A E MONTANA B A WYOMING B A UTAH B A ARIZONA B N COLORADO N N NEW MEXICO N N N DAKOTA B A S DAKOTA B A NEBRASKA N N KANSAS N A OKLAHOMA A A N TEXAS A A S TEXAS A N W TEXAS N A MINNESOTA N A IOWA N N MISSOURI A A ARKANSAS A A LOUISIANA A N WISCONSIN N A ILLINOIS A N MISSISSIPPI A B MICHIGAN A A INDIANA A N OHIO A N KENTUCKY A N TENNESSEE A B ALABAMA A B NEW YORK A N VERMONT A N NEW HAMP A N MAINE A B MASS A B CONN A B RHODE IS A B PENN A N NEW JERSEY A B W VIRGINIA A N MARYLAND A B DELAWARE A B VIRGINIA A B N CAROLINA A B S CAROLINA A B GEORGIA A B FL PNHDL A B FL PENIN A B AK N SLOPE A A AK ALEUTIAN A N AK WESTERN A A AK INT BSN A A AK S INT B B AK SO COAST B B AK PNHDL B B 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. $$