PROGNOSTIC DISCUSSIONS FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS NWS CLIMATE PREDICTION CENTER CAMP SPRINGS MD 300 PM EDT THU MAY 10 2007 6-10 DAY OUTLOOK VALID FOR MAY 16 - 20 2007 AVAILABLE NUMERICAL MODELS FROM THE LAST 24 HOURS ARE IN GOOD AGREEMENT ON THE EXPECTED 500-HPA HEIGHT PATTERN OVER NORTH AMERICA DURING THE 6-10 DAY FORECAST PERIOD. HOWEVER... THERE ARE SOME SIGNIFICANT CHANGES FROM YESTERDAYS 6-10 DAY FORECASTS. THE TROUGH OVER THE NORTH PACIFIC HAS WEAKENED COMPARED TO MOST MODEL SOLUTIONS FROM THE LAST SEVERAL DAYS. DOWNSTREAM OVER THE CONUS... A RIDGE OVER THE WEST HAS WIDENED SLIGHTLY IN THE 0Z ENSEMBLE MEAN SOLUTION... WHILE THE 6Z OPERATIONAL MODEL IS FORECASTING FAST ZONAL FLOW ACROSS THE NORTHERN TIER. A TROUGH CENTERED OVER THE LABRADOR SEA HAS WEAKENED AND RETROGRESSED SLIGHTLY WESTWARD IN TODAYS 0Z AND 6Z GFS AND YESTERDAYS 12Z ECMWF ENSEMBLE MEANS. AN AREA OF MODEL DISAGREEMENT CONTINUES TO BE HOW MUCH THIS TROUGH INFLUENCES THE U.S. EASTERN SEABOARD... ALLOWING COLDER AIR FROM CANADA TO INFLUENCE THIS REGION. TODAYS OFFICIAL BLENDED 500-HPA HEIGHT FIELD STILL INDICATES GOOD CONTINUITY WITH YESTERDAYS FORECAST DESPITE SOME CHANGES IN THE MODEL SOLUTIONS... WITH 500-HPA HEIGHTS SLIGHTLY HIGHER OVER THE NORTHEAST. WARMER THAN NORMAL TEMPERATURES ARE EXPECTED FOR THE WESTERN CONUS UNDER THE RIDGE EXTENDING SOUTHEASTWARD INTO THE MISSISSIPPI VALLEY. BELOW NORMAL TEMPERATURES ARE FORECAST FOR NEW ENGLAND UNDER THE TROUGH AND NORTHWESTERLY FLOW. SOUTHEASTERN ALASKA AND THE ALASKAN PANHANDLE SHOULD BE WARMER THAN NORMAL UNDER FORECAST SOUTHWESTERLY FLOW... WHILE NORTHERN AND WESTERN REGIONS OF THE STATE SHOULD BE COOLER THAN NORMAL UNDER NORTHERLY FLOW. ABOVE NORMAL PRECIPITATION IS FORECAST FROM THE OHIO VALLEY EASTWARD INTO THE MID-ATLANTIC STATES DUE TO SHORTWAVES EXPECTED TO DROP SOUTH AHEAD OF THE WESTERN U.S. RIDGE. ABOVE NORMAL PRECIPITATION IS ALSO EXPECTED FOR PARTS OF NEW MEXICO... TEXAS AND THE GULF COAST. UNDER THE WESTERN U.S. RIDGE... BELOW NORMAL PRECIPITATION IS EXPECTED IN THE PACIFIC NORTHWEST. BELOW AVERAGE PRECIPITATION IS EXPECTED FOR WESTERN ALASKA... WHILE ABOVE NORMAL PRECIPITATION IS LIKELY FOR THE ALASKAN PANHANDLE. TODAYS OFFICIAL 500-HPA BLEND CONSISTS OF 5 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 0Z GFS ENSEMBLE MEAN CENTERED ON DAY 8...30 PERCENT OF TODAY'S 6Z GFS ENSEMBLE MEAN CENTERED ON DAY 8...15 PERCENT OF TODAY'S CANADIAN ENSEMBLE MEAN CENTERED ON DAY 8...AND 25 PERCENT OF TODAY'S EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 7. MODEL(S) OF THE DAY: 6Z GFS ENSEMBLE MEAN. FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD IS ABOUT AVERAGE... 3 ON A SCALE OF 1 TO 5.... DUE TO GOOD MODEL AGREEMENT WITH SOME DISAGREEMENT AMONG THE TOOLS. THE 6-10 DAY TEMPERATURE PROG IS BASED ON THE KLEIN... NEURAL NET AND ANALOG SPECIFICATIONS FROM THE OFFICIAL BLENDED HEIGHT FIELD AND FROM THE VARIOUS MODEL HEIGHT FIELDS... THE NORTH AMERICAN ENSEMBLE FORECAST SYSTEM TEMPERATURE GUIDANCE... THE CPC AUTO TEMPERATURE FORECAST... AND THE CDC TEMPERATURE TOOL. THE 6-10 DAY PRECIPITATION PROG IS BASED ON THE ANALOG SPECIFICATIONS FROM THE OFFICIAL BLENDED HEIGHT FIELD AND FROM THE VARIOUS MODEL HEIGHT FIELDS... THE CPC AUTO PRECIPITATION FORECAST... AND THE CDC PRECIPITATION TOOL. 8-14 DAY OUTLOOK FOR MAY 18 - 24 2007: THE FORECAST 500-HPA HEIGHT PATTERN FOR THE 8-14 DAY PERIOD INDICATES A MORE ZONAL FLOW PATTERN THAN THAT FORECAST FOR THE 6-10 DAY PERIOD... WITH HEIGHTS SLIGHTLY ABOVE NORMAL OVER MOST OF THE CONUS. UNLIKE THE 0Z AND 6Z GFS ENSEMBLE MEANS... THE CANADIAN ENSEMBLE MEAN FORECASTS A WEAKNESS IN THE RIDGE OVER THE EASTERN CONUS. THE OFFICIAL BLENDED 500-HPA HEIGHTS FOR THE 8-14 DAY PERIOD INDICATE A BROAD RIDGE FROM COAST TO COAST... AND A SPLIT FLOW BEGINNING AT THE WEST COAST. FOR THE 8-14 DAY FORECAST PERIOD... THE EXPECTED PRECIPITATION AND TEMPERATURE ANOMALIES ARE SIGNIFICANTLY WEAKER THAN FORECAST FOR THE 6-10 DAY PERIOD. ABOVE NORMAL TEMPERATURES ARE FORECAST FOR THE WESTERN AND NORTHERN CONUS INTO THE CENTRAL MISSISSIPPI VALLEY. PRECIPITATION IS FORECAST TO BE NEAR NORMAL FOR MOST OF THE CONUS WITH AN AREA OF ABOVE AVERAGE PRECIPITATION FORECAST FOR TEXAS... ALONG THE GULF COAST... AND THE SOUTHEAST COASTAL STATES NORTHWARD TO THE CHESAPEAKE BAY. ABOVE NORMAL PRECIPITATION IS FORECAST FOR THE ALASKAN PANHANDLE... WHILE BELOW NORMAL PRECIPITATION IS EXPECTED FOR THE NORTH SLOPE AND WESTERN ALEUTIANS. THE OFFICIAL 8-14 DAY HEIGHT PROG CONSISTS OF 5 PERCENT OF TODAY'S OPERATIONAL 0Z GFS CENTERED ON DAY 11...5 PERCENT OF TODAY'S OPERATIONAL 6Z GFS CENTERED ON DAY 11...25 PERCENT OF TODAY'S 0Z GFS ENSEMBLE MEAN CENTERED ON DAY 11...40 PERCENT OF TODAY'S 6Z GFS ENSEMBLE MEAN CENTERED ON DAY 11...AND 25 PERCENT OF TODAY'S CANADIAN ENSEMBLE MEAN CENTERED ON DAY 11. FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD IS ABOUT AVERAGE... 3 ON A SCALE OF 1 TO 5... DUE TO GOOD MODEL AGREEMENT WITH ONLY FAIR AGREEMENT AMONG THE TOOLS. THE 8-14 DAY TEMPERATURE PROG IS BASED ON THE KLEIN... NEURAL NET AND ANALOG SPECIFICATIONS FROM THE OFFICIAL BLENDED HEIGHT FIELD AND FROM THE VARIOUS MODEL HEIGHT FIELDS... THE NORTH AMERICAN ENSEMBLE FORECAST SYSTEM TEMPERATURE GUIDANCE... THE CPC AUTO TEMPERATURE FORECAST... AND THE CDC TEMPERATURE TOOL. THE 8-14 DAY PRECIPITATION PROG IS BASED ON THE ANALOG SPECIFICATIONS FROM THE OFFICIAL BLENDED HEIGHT FIELD AND FROM THE VARIOUS MODEL HEIGHT FIELDS... THE CPC AUTO PRECIPITATION FORECAST... AND THE CDC PRECIPITATION TOOL. FORECASTER: D. 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 MAY 17. 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: 19990501 - 19900425 - 19910521 - 19890517 - 19920510 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: 19900424 - 19990430 - 19910521 - 19890517 - 19860510 6 to 10 day Outlook Table OUTLOOK FOR MAY 16 - 20, 2007 STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN WASHINGTON A N OREGON A N NRN CALIF A N SRN CALIF A N IDAHO A B NEVADA A N W MONTANA A B E MONTANA A B WYOMING A B UTAH A N ARIZONA A N COLORADO N N NEW MEXICO N N N DAKOTA A B S DAKOTA A N NEBRASKA A N KANSAS N N OKLAHOMA N A N TEXAS B A S TEXAS B A W TEXAS B A MINNESOTA A N IOWA A N MISSOURI A N ARKANSAS N N LOUISIANA N A WISCONSIN N N ILLINOIS A N MISSISSIPPI N N MICHIGAN N A INDIANA N A OHIO N A KENTUCKY N A TENNESSEE A N ALABAMA N N NEW YORK B A VERMONT B N NEW HAMP B N MAINE B N MASS B N CONN B A RHODE IS B A PENN N A NEW JERSEY N A W VIRGINIA N A MARYLAND N A DELAWARE N A VIRGINIA N A N CAROLINA N A S CAROLINA N N GEORGIA N N FL PNHDL N A FL PENIN N A AK N SLOPE B N AK ALEUTIAN B B AK WESTERN B B AK INT BSN N N AK S INT A N AK SO COAST A N AK PNHDL A A 8 to 14 day Outlook Table OUTLOOK FOR MAY 18 - 24, 2007 STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN WASHINGTON A N OREGON A N NRN CALIF A N SRN CALIF A N IDAHO A N NEVADA A N W MONTANA A N E MONTANA A N WYOMING A N UTAH A N ARIZONA A N COLORADO A N NEW MEXICO N N N DAKOTA A N S DAKOTA A N NEBRASKA A N KANSAS N N OKLAHOMA N A N TEXAS B A S TEXAS B A W TEXAS B A MINNESOTA A N IOWA A N MISSOURI A N ARKANSAS A N LOUISIANA N A WISCONSIN A N ILLINOIS A N MISSISSIPPI N A MICHIGAN A N INDIANA A N OHIO A N KENTUCKY A N TENNESSEE A N ALABAMA N 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 N NEW JERSEY N N W VIRGINIA N N MARYLAND N N DELAWARE N N VIRGINIA N N N CAROLINA N A S CAROLINA N A GEORGIA N A FL PNHDL N A FL PENIN N A AK N SLOPE B B AK ALEUTIAN N N AK WESTERN N B AK INT BSN N N AK S INT N N AK SO COAST N N 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. $$