PROGNOSTIC DISCUSSIONS FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS NWS CLIMATE PREDICTION CENTER CAMP SPRINGS MD 300 PM EDT FRI SEP 12 2008 6-10 DAY OUTLOOK VALID FOR SEP 18 - 22 2008 TODAYS ENSEMBLE MEAN MODEL SOLUTIONS ARE IN FAIR AGREEMENT ON THE 500-HPA HEIGHT PATTERN EXPECTED OVER THE FORECAST DOMAIN DURING THE 6-10 DAY PERIOD. TROUGHS ARE FORECAST OVER WESTERN ALASKA AND THE SOUTHEAST CONUS WHILE A WEAK RIDGE IS EXPECTED NEAR THE WEST COAST OF CANADA. ALL MODEL ENSEMBLE MEANS DEPICT A TROUGH OR CLOSED LOW NEAR THE CALIFORNIA COAST, THOUGH THERE ARE LARGE DIFFERENCES WITH THIS FEATURE AMONG INDIVIDUAL ENSEMBLE MEMBERS AND THE OPERATIONAL MODEL RUNS. THE ECMWF ENSEMBLE MEAN FLOW PATTERN IS SLIGHTLY MORE PROGRESSIVE OVERALL THAN THE GFS AND CANADIAN ENSEMBLE MEANS. TODAYS OFFICIAL 500-HPA HEIGHT BLEND WEIGHTS THE ECMWF ENSEMBLE MEAN SLIGHTLY MORE THAN THE GFS AND CANADIAN MODELS DUE TO HIGHER MEAN ANOMALY CORRELATIONS TO THE OBSERVED HEIGHT PATTERNS OVER NORTH AMERICA DURING THE PAST 60 DAYS. THE OFFICIAL BLEND INDICATES NEAR TO BELOW NORMAL HEIGHTS FOR THE GULF COAST STATES AND FOR EASTERN ALASKA AND THE ALASKAN PANHANDLE. NEAR TO ABOVE NORMAL 500-HPA HEIGHTS ARE FORECAST FROM THE SOUTHWEST CONUS EXTENDING THROUGH THE NORTHERN PLAINS INTO THE NORTHEAST. NEAR TO ABOVE MEDIAN PRECIPITATION IS EXPECTED FOR THE SOUTHEAST US STATES AND BELOW NORMAL TEMPERATURES ARE FORECAST FOR THE SOUTHERN PLAINS INTO THE SOUTHEAST AND NORTHWARD INTO THE OHIO VALLEY, DUE TO A FORECAST WEAKNESS IN THE SUBTROPICAL RIDGE IN THIS REGION. FURTHER UPSTREAM, WARMER THAN NORMAL CONDITIONS ARE EXPECTED FOR MOST OF THE WESTERN CONUS AND THE NORTHERN PLAINS UNDER POSITIVE HEIGHT ANOMALIES. SHORTWAVE ENERGY MAY BRING PRECIPITATION TO CANADIAN BORDER STATES. THE TROUGH FORECAST NEAR THE CALIFORNIA COAST MAY PROVIDE ENOUGH RAINFALL FOR ABOVE MEDIAN PRECIPITATION FOR PARTS OF THE INTERIOR SOUTHWEST, THOUGH UNCERTAINTY IS HIGH. ABOVE MEDIAN PRECIPITATION IS EXPECTED FOR THE ALASKAN PANHANDLE AHEAD OF THE TROUGH FORECAST OVER THE WESTERN PART OF THE STATE. ABOVE NORMAL TEMPERATURES ARE FORECAST FOR MUCH OF ALASKA UNDER SOUTHERLY FLOW. TODAYS OFFICIAL 500-HPA BLEND CONSISTS OF 5 PERCENT OF TODAY'S OPERATIONAL 0Z GFS CENTERED ON DAY 8...5 PERCENT OF TODAY'S OPERATIONAL 6Z GFS CENTERED ON DAY 8...10 PERCENT OF TODAY'S OPERATIONAL ECMWF CENTERED ON DAY 7...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...10 PERCENT OF TODAY'S CANADIAN ENSEMBLE MEAN CENTERED ON DAY 8...AND 40 PERCENT OF TODAY'S EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 7. MODEL(S) OF THE DAY: ECMWF ENSEMBLE MEAN FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD IS AVERAGE, 3 ON A SCALE OF 1 TO 5 DUE TO ONLY FAIR AGREEMENT AMONG THE MODEL ENSEMBLE MEANS WITH GOOD AGREEMENT IN MOST OF THE TOOLS. THE 6-10 DAY TEMPERATURE PROG IS BASED ON THE KLEIN AND ANALOG SPECIFICATIONS FROM THE OFFICIAL BLEND, THE NORTH AMERICAN ENSEMBLE FORECAST SYSTEM (NAEFS) TEMPERATURE GUIDANCE, THE CDC TEMPERATURE FORECAST, AND THE AUTO TEMPERATURE FORECAST. THE 6-10 DAY PRECIPITATION PROG IS BASED ON THE ANALOG SPECIFICATIONS FROM THE OFFICIAL BLEND AND VARIOUS MODEL FORECASTS, THE AUTO PRECIPITATION FORECAST, AND THE NORTH AMERICAN ENSEMBLE FORECAST SYSTEM (NAEFS) PRECIPITATION PROBABILITY FORECASTS. 8-14 DAY OUTLOOK FOR SEP 20 - 26 2008: FOR WEEK TWO, THE FORECAST 500-HPA HEIGHT FIELDS FROM THE GFS AND CANADIAN ENSEMBLE MEANS ARE IN FAIR AGREEMENT. HOWEVER, SPREAD AMONG THEIR COMPONENT ENSEMBLE MEMBERS IS HIGHER THAN USUAL. TROUGHS ARE FORECAST NEAR WESTERN ALASKA AND THE SOUTHEASTERN US WITH MOSTLY ZONAL FLOW IN BETWEEN. A TROUGH IS ALSO DEPICTED NEAR THE CALIFORNIA COAST, ALTHOUGH ENSEMBLE MEMBER DISAGREEMENT IS VERY HIGH WITH THIS FEATURE. TODAYS OFFICIAL 500-HPA HEIGHT BLEND IS A NEARLY EQUAL COMBINATION OF THE 00Z CANADIAN AND 00Z AND 06Z GFS ENSEMBLE MEANS. THE BLEND INDICATES NEAR TO ABOVE NORMAL HEIGHTS FOR WESTERN ALASKA AND THE NORTHWESTERN TWO-THIRDS OF THE CONUS. NEAR TO BELOW NORMAL HEIGHTS ARE DEPICTED FOR MOST OF THE SOUTHEASTERN CONUS. NEAR TO ABOVE MEDIAN PRECIPITATION IS EXPECTED FOR MUCH OF THE SOUTHEAST DUE TO A FORECAST WEAKNESS IN THE SUBTROPICAL RIDGE OVER THE AREA. SHORTWAVE ENERGY IN THE MEAN JET MAY BRING ABOVE MEDIAN PRECIPITATION TO THE ALASKAN PANHANDLE AND PARTS OF THE NORTHERN TIER STATES. MONSOONAL MOISTURE MAY LEAD TO ABOVE NORMAL PRECIPITATION FOR PARTS OF THE HIGH PLAINS. ABOVE NORMAL TEMPERATURES ARE EXPECTED WEST OF THE ROCKIES UNDER POSITIVE HEIGHT ANOMALIES. THE OFFICIAL 8-14 DAY HEIGHT PROG CONSISTS OF 35 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 30 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 TO ONLY FAIR MODEL ENSEMBLE MEAN AGREEMENT AND LARGE UNCERTAINTY AMONG ENSEMBLE MEMBERS. THE 8-14 DAY TEMPERATURE PROG IS BASED ON THE KLEIN AND ANALOG SPECIFICATIONS FROM THE OFFICIAL BLEND, THE NORTH AMERICAN ENSEMBLE FORECAST SYSTEM (NAEFS) TEMPERATURE GUIDANCE, THE CDC TEMPERATURE FORECAST, AND THE AUTO TEMPERATURE FORECAST. THE 8-14 DAY PRECIPITATION PROG IS BASED ON THE ANALOG SPECIFICATIONS FROM THE OFFICIAL BLEND, THE CDC PRECIPITATION FORECAST, THE AUTO PRECIPITATION FORECAST, AND THE NORTH AMERICAN ENSEMBLE FORECAST SYSTEM (NAEFS) PRECIPITATION PROBABILITY FORECASTS. FORECASTER: COLLINS 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 SEPTEMBER 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: 19800924 - 19740912 - 19650922 - 19700915 - 19930925 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: 19650922 - 19800924 - 19740912 - 19930830 - 19720901 6 to 10 day Outlook Table OUTLOOK FOR SEP 18 - 22, 2008 STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN WASHINGTON A N OREGON A B NRN CALIF A B SRN CALIF A N IDAHO A B NEVADA A N W MONTANA A N E MONTANA A B WYOMING A N UTAH A N ARIZONA A N COLORADO N A NEW MEXICO N N N DAKOTA A N S DAKOTA A B NEBRASKA N B KANSAS N B OKLAHOMA B B N TEXAS B B S TEXAS B B W TEXAS B B MINNESOTA A N IOWA N B MISSOURI B B ARKANSAS B B LOUISIANA B B WISCONSIN N N ILLINOIS B B MISSISSIPPI B N MICHIGAN N N INDIANA B B OHIO B B KENTUCKY B B TENNESSEE B N ALABAMA B A NEW YORK N N VERMONT N N NEW HAMP N N MAINE N N MASS N N CONN N N RHODE IS N N PENN N B NEW JERSEY N N W VIRGINIA B N MARYLAND N N DELAWARE N N VIRGINIA B N N CAROLINA B A S CAROLINA B A GEORGIA B A FL PNHDL B A FL PENIN B A AK N SLOPE A N AK ALEUTIAN N B AK WESTERN A B AK INT BSN A N AK S INT A N AK SO COAST A N AK PNHDL N A 8 to 14 day Outlook Table OUTLOOK FOR SEP 20 - 26, 2008 STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN WASHINGTON A A OREGON A B NRN CALIF A B SRN CALIF A B IDAHO A B NEVADA A B W MONTANA A N E MONTANA N N WYOMING N N UTAH A B ARIZONA A N COLORADO N A NEW MEXICO N B N DAKOTA N A S DAKOTA N A NEBRASKA N N KANSAS N B OKLAHOMA N B N TEXAS B B S TEXAS B B W TEXAS N B MINNESOTA N A IOWA N N MISSOURI B B ARKANSAS B B LOUISIANA B B WISCONSIN N N ILLINOIS B B MISSISSIPPI B N MICHIGAN N N INDIANA B B OHIO B B KENTUCKY B B TENNESSEE B B ALABAMA B N NEW YORK N B VERMONT N N NEW HAMP N B MAINE N N MASS N B CONN N B RHODE IS N B PENN N B NEW JERSEY N B W VIRGINIA B B MARYLAND B B DELAWARE B B VIRGINIA B N N CAROLINA B A S CAROLINA B A GEORGIA B A FL PNHDL B A FL PENIN N A AK N SLOPE A N AK ALEUTIAN N N AK WESTERN A B AK INT BSN A N AK S INT A A AK SO COAST A A AK PNHDL N A 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. $$