PROGNOSTIC DISCUSSIONS FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS NWS CLIMATE PREDICTION CENTER CAMP SPRINGS MD 300 PM EDT FRI AUG 29 2008 6-10 DAY OUTLOOK VALID FOR SEP 04 - 08 2008 THE ENSEMBLE MEAN SOLUTIONS ARE IN LESS AGREEMENT FOR THE MEAN 500-HPA HEIGHT PATTERN TODAY THAN YESTERDAY. THE GFS 00Z AND 06Z ENSEMBLE MEAN SOLUTIONS PREFER A MEAN TROUGH ACROSS THE CENTRAL US AS OPPOSED TO THE ECMWF 00Z ENSEMBLE MEAN WHICH INDICATES A MORE AMPLIFIED PATTERN WITH DEEPER TROUGHING FURTHER WEST AND A MORE AMPLIFIED RIDGE ACROSS THE NORTHEAST US. THE CANADIAN ENSEMBLE MEAN DIFFERS AS WELL AND A MEAN TROUGH ACROSS THE EASTERN US IS FAVORED IN THIS MODEL. THE GFS AND ECMWF SOLUTIONS WERE PREFERRED BASED ON RECENT VERIFICATION AND A MORE PLAUSIBLE SOLUTION BASED ON RECENT OBSERVATIONS. THE OPERATIONAL RUNS FROM THE 00Z AND 06Z GFS ARE GENERALLY CONSISTENT BETWEEN EACH OTHER AND WITH THEIR RESPECTIVE ENSEMBLE MEANS. THE 500-HPA HEIGHT OFFICIAL BLEND FAVORS THE ENSEMBLE MEAN SOLUTIONS OF THE GFS AND ECMWF BUT INCLUDES WEIGHT FROM BOTH THE 00Z AND 06Z OPERATIONAL GFS. THE CANADIAN ENSEMBLE MEAN WAS NOT INCLUDED IN THE OFFICAL BLEND FOR TODAY. BASED ON THE ABOVE THINKING, A MEAN TROUGH IS EXPECTED TO SITUATE ITSELF ACROSS WEST-CENTRAL US WITH A RIDGE ACROSS THE EXTREME NORTHEAST PORTION OF THE US AND SOUTHEAST CANADA. AS A RESULT OF THIS FORECAST PATTERN, ABOVE-AVERAGE TEMPERATURES ARE EXPECTED TO PREVAIL ACROSS PARTS OF THE NORTHEAST US DUE TO THIS RIDGE AND ABOVE-AVERAGE HEIGHTS IN THIS AREA. FAVORABLE ORIENTATION OF SUB-TROPICAL RIDGING ACROSS THE ATLANTIC BASIN WILL ALLOW NUMEROUS TROPICAL DISTURBANCES AND CONTINUED AMPLE MOISTURE FLOW TO IMPACT THE GULF COAST AND SOUTHEAST US WITH ABOVE-MEDIAN PRECIPITATION DURING THE PERIOD. TROPICAL SYSTEMS GUSTAV AND HANNAH ARE LIKELY TO IMPACT LARGE PORTIONS OF THE SOUTHEAST US. A WEAKNESS IN THIS RIDGE IS EXPECTED TO ALLOW ENHANCED FLOW AHEAD OF THE WEST-CENTRAL US TROUGH INCREASING CHANCES FOR ABOVE-MEDIAN PRECIPITATION ACROSS THE CENTRAL PART OF THE COUNTRY AS THIS MOISTURE INTERACTS WITH FRONTAL SYSTEMS ACROSS THE NORTHERN PLAINS. THE MEAN TROUGH ACROSS THE CENTRAL US AND EXTENSIVE CLOUD COVER SHOULD LEAD TO COOLER THAN AVERAGE TEMPERATURES ACROSS PARTS OF THE CENTRAL AND SOUTHERN US. RIDGING IS EXPECTED TO BUILD IN ALONG THE WEST COAST AND IS EXPECTED TO RESULT IN DRIER THAN AVERAGE CONDITIONS AND ABOVE-AVERAGE TEMPERATURES IN THE PACIFIC NORTHWEST. TODAYS OFFICIAL 500-HPA BLEND CONSISTS OF 15 PERCENT OF TODAY'S OPERATIONAL 6Z GFS CENTERED ON DAY 8...10 PERCENT OF TODAY'S OPERATIONAL ECMWF CENTERED ON DAY 7...25 PERCENT OF TODAY'S 0Z GFS ENSEMBLE MEAN CENTERED ON DAY 8...25 PERCENT OF TODAY'S 6Z GFS ENSEMBLE MEAN CENTERED ON DAY 8...AND 25 PERCENT OF TODAY'S EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 7. MODEL(S) OF THE DAY: TIED BETWEEN 0Z GFS, 6Z GFS, AND 0Z ECMWF ENSEMBLE MEANS FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD IS NEAR-AVERAGE, 3 ON A SCALE OF 1 TO 5 DUE TO GENERALLY GOO AGREEMENT IN THE FORECAST TOOLS OFFSET BY SOME DIFFERENCES IN ENSEMBLE MEAN SOLUTIONS AND UNCERTAINTY IN THE EVOLUTION OF TROPICAL SYSTEMS ACROSS THE SOUTH AND EAST US DURING THE PERIOD. THE 6-10 DAY TEMPERATURE PROG IS BASED ON THE KLEIN AND ANALOG SPECIFICATIONS FROM THE OFFICIAL BLEND, THE AUTO TEMPERATURE FORECAST, THE NORTH AMERICAN ENSEMBLE FORECAST SYSTEM (NAEFS) TEMPERATURE PROBABILITY FORECASTS, THE KLEIN PROBABILITIES FROM THE VARIOUS ENSEMBLES INCLUDING THE SUPERENSEMBLE. THE 6-10 DAY PRECIPITATION PROG IS BASED ON THE ANALOG AND NEURAL NET SPECIFICATIONS FROM THE OFFICIAL BLEND AND VARIOUS ENSEMBLE MEAN FORECASTS, THE AUTO PRECIPITATION FORECAST, THE NORTH AMERICAN ENSEMBLE FORECAST SYSTEM (NAEFS) PRECIPITATION PROBABILITY FORECASTS AND INSPECTION OF OPERATIONAL MODEL RUNS FROM VARIOUS CENTERS. 8-14 DAY OUTLOOK FOR SEP 06 - 12 2008: THERE IS BETTER AGREEMENT AMONG THE ENSEMBLE MEAN SOLUTIONS DURING THE 8-14 DAY PERIOD THAN THE 6-10 DAY PERIOD. AVAILABLE ENSEMBLE MEAN SOLUTIONS AGREE IN PLACING A DISTINCT MEAN TROUGH ACROSS THE EAST-CENTRAL US WITH ABOVE AVERAGE HEIGHTS ACROSS THE WEST COAST AND WESTERN CANADA. THE OFFICAL BLEND FORECAST OF THE 500-HPA HEIGHT PATTERN IS BASED ON THE 6Z AND 0Z GFS AND 0Z CANADIAN ENSEMBLE MEAN SOLUTIONS. THE OFFICIAL BLEND 500-HPA PATTERN REFLECTS A SIGNIFICANT WEAKNESS IN THE SUBTROPICAL RIDGE ALONG THE GULF COAST DURING THIS PERIOD AND IS EXPECTED TO RESULT IN GREATER CHANCES FOR ABOVE-MEDIAN PRECIPITATION ACROSS THE SOUTHEAST US INTO PARTS OF THE OHIO VALLEY AND NORTHEAST AHEAD OF THE MEAN TROUGH IN THE CENTRAL US. IN ADDITION, TROPICAL DISTURBANCES MAY ALSO CONTRIBUTE TO INCREASED PRECIPITATION IN SOME OF THESE AREAS. BELOW-AVERAGE 500-HPA HEIGHTS ARE EXPECTED TO RESULT IN BELOW-AVERAGE TEMPERATURES ACROSS THE CENTRAL US, SOUTHEAST US AND OHIO VALLEY. ANTICIPATED RIDGING ACROSS THE WESTERN US SHOULD LEAD TO WARMER THAN AVERAGE CONDITIONS ALONG THE WEST COAST AND DRIER THAN AVERAGE CONDITIONS IN THE PACIFIC NORTHWEST. A ROBUST TROUGH IN THE NORTHERN PACIFIC IS EXPECTED TO LEAD TO ABOVE-MEDIAN PRECIPITATION ACROSS THE ALASKA PANHANDLE DURING THE PERIOD. THE OFFICIAL 8-14 DAY HEIGHT PROG CONSISTS OF 20 PERCENT OF TODAY'S 0Z GFS ENSEMBLE MEAN CENTERED ON DAY 11...30 PERCENT OF TODAY'S 6Z GFS ENSEMBLE MEAN CENTERED ON DAY 11...20 PERCENT OF TODAY'S GFS SUPERENSEMBLE 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 NEAR-AVERAGE, 3 ON A SCALE OF 1 TO 5 DUE TO REASONABLE WEEK 2 AGREEMENT IN THE ENSEMBLE MEAN SOLUTIONS OFFSET BY LARGE UNCERTAINTIES FOR FUTURE DEVELOPMENTS IN THE TROPICS. 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 PROBABILITY FORECASTS, AND THE KLEIN PROBABILITIES FROM THE GFS ENSEMBLES MEAN FORECASTS INCLUDING THE SUPERENSEMBLE. THE 8-14 DAY PRECIPITATION PROG IS BASED ON THE NEURAL NET SPECIFICATION FROM THE OFFICIAL BLEND, NORTH AMERICAN ENSEMBLE FORECAST SYSTEM (NAEFS) PRECIPITATION PROBABILITY FORECASTS AND THE AUTO BLEND PRECIPITATION FORECAST. FORECASTER: GOTTSCHALCK 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: 19680909 - 19700813 - 19960911 - 19710910 - 19520822 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: 19680909 - 19700813 - 19710909 - 19980809 - 19960910 6 to 10 day Outlook Table OUTLOOK FOR SEP 04 - 08, 2008 STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN WASHINGTON N B OREGON N B NRN CALIF A N SRN CALIF N N IDAHO N N NEVADA N N W MONTANA B N E MONTANA B A WYOMING B N UTAH N N ARIZONA N N COLORADO B A NEW MEXICO B N N DAKOTA B A S DAKOTA B A NEBRASKA B A KANSAS B A OKLAHOMA B A N TEXAS B A S TEXAS B A W TEXAS B A MINNESOTA N A IOWA B A MISSOURI B A ARKANSAS B A LOUISIANA B A WISCONSIN N A ILLINOIS N A MISSISSIPPI B A MICHIGAN N N INDIANA N A OHIO N N KENTUCKY N A TENNESSEE N A ALABAMA B A 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 N N MARYLAND A N DELAWARE A N VIRGINIA N A N CAROLINA N A S CAROLINA N A GEORGIA N A FL PNHDL B A FL PENIN B A AK N SLOPE A N AK ALEUTIAN N N AK WESTERN N A AK INT BSN A N AK S INT N A AK SO COAST N A AK PNHDL N A 8 to 14 day Outlook Table OUTLOOK FOR SEP 06 - 12, 2008 STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN WASHINGTON A B OREGON A B NRN CALIF A N SRN CALIF A N IDAHO A B NEVADA A N W MONTANA N B E MONTANA N B WYOMING N N UTAH N N ARIZONA N N COLORADO B N NEW MEXICO N N N DAKOTA B N S DAKOTA B N NEBRASKA B N KANSAS B N OKLAHOMA B A N TEXAS B A S TEXAS B A W TEXAS B N MINNESOTA B N IOWA B N MISSOURI B A ARKANSAS B A LOUISIANA B A WISCONSIN B N ILLINOIS B A MISSISSIPPI B A MICHIGAN N N INDIANA B A OHIO B A KENTUCKY B A TENNESSEE B A ALABAMA B A NEW YORK N A VERMONT A N NEW HAMP A A MAINE A N MASS A A CONN N A RHODE IS N A PENN N A NEW JERSEY N A W VIRGINIA B A MARYLAND N A DELAWARE N A VIRGINIA B A N CAROLINA B A S CAROLINA B A GEORGIA B A FL PNHDL B A FL PENIN B A AK N SLOPE N N AK ALEUTIAN N B AK WESTERN N B AK INT BSN N N AK S INT N N AK SO COAST N N 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. $$