PROGNOSTIC DISCUSSIONS FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS NWS CLIMATE PREDICTION CENTER CAMP SPRINGS MD 300 PM EST FRI DEC 21 2007 6-10 DAY OUTLOOK VALID FOR DEC 27 - 31 2007 TODAYS MODEL GUIDANCE IS IN EXCELLENT AGREEMENT ON THE EXPECTED 500-HPA FLOW PATTERN. CONTINUITY REMAINS GOOD AND ENSEMBLE MEAN SOLUTIONS MAINTAIN A PERSISTENT LONGWAVE PATTERN ACROSS THE PACIFIC AND NORTH AMERICA. ALL MODEL SOLUTIONS FEATURE A DEEP TROUGH EXTENDING FROM ALASKA INTO THE WEST-CENTRAL CONUS... A SUBTROPICAL RIDGE STRETCHING ACROSS THE EAST PACIFIC... AND A MODERATELY STRONG RIDGE OVER THE SOUTHWEST ATLANTIC. THE OFFICIAL BLENDED 500-HPA HEIGHT FIELD INDICATES NEGATIVE 500-HPA HEIGHT ANOMALIES FROM ALASKA INTO WESTERN NORTH AMERICA WITH POSITIVE 500-HPA HEIGHT ANOMALIES OVER THE EAST-CENTRAL PACIFIC AND THE EASTERN THIRD OF NORTH AMERICA. TELECONNECTIONS ON THE LARGE NEGATIVE 500-HPA HEIGHT ANOMALY CENTERED IN THE NORTHERN GULF OF ALASKA SUPPORT ABOVE NORMAL TEMPERATURES ACROSS THE EASTERN CONUS AND ABOVE NORMAL PRECIPITATION ACROSS THE PACIFIC NORTHWEST AND NORTHERN CALIFORNIA. FOR THE REMAINDER OF THE CONUS THE SIGNAL FROM THE TELECONNECTION IS WEAK. TEMPERATURES ARE FORECAST TO BE ABOVE NORMAL FROM THE MISSISSIPPI VALLEY TO THE EAST COAST WITH BELOW NORMAL TEMPERATURES EXPECTED ACROSS CALIFORNIA... THE SOUTHWEST... GREAT BASIN... AND WESTERN ALASKA. THE DEEP TROUGH WILL LIKELY BRING A SERIES OF STRONG PACIFIC STORMS AND ABOVE NORMAL PRECIPITATION TO THE ALEUTIANS... SOUTHWEST ALASKA... AND THE WEST COAST. AS STORMS TRACK EAST... ABOVE NORMAL PRECIPITATION IS ALSO FORECAST FOR THE CENTRAL AND SOUTHERN ROCKIES. THE PRIMARY STORM TRACK IS EXPECTED TO PERSIST FROM THE LOWER MISSISSIPPI VALLEY INTO THE OHIO VALLEY AND NORTHEAST. THESE AREAS WILL LIKELY RECEIVE ABOVE NORMAL PRECIPITATION. THE GREATEST UNCERTAINTY EXISTS IN THE DROUGHT PARCHED AREAS OF THE SOUTHEAST WHERE PRECIPITATION TOOLS DIFFER. PRECIPITATION AMOUNTS WILL DEPEND UPON THE STRENGTH OF THE SOUTHWEST ATLANTIC RIDGE. THE OUTLOOK CALLS FOR A TIGHT GRADIENT BETWEEN ABOVE AND BELOW NORMAL PRECIPITATION IN THE SOUTHEAST WITH THE FLORIDA PENINSULA MOST LIKELY RECEIVING BELOW NORMAL PRECIPITATION. BENEFICIAL RAINFALL IS EXPECTED ACROSS ALABAMA AND NORTH GEORGIA. 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...20 PERCENT OF TODAY'S OPERATIONAL ECMWF CENTERED ON DAY 7...10 PERCENT OF TODAY'S 0Z GFS ENSEMBLE MEAN CENTERED ON DAY 8...10 PERCENT OF TODAY'S 6Z GFS ENSEMBLE MEAN CENTERED ON DAY 8...10 PERCENT OF TODAY'S GFS SUPERENSEMBLE MEAN CENTERED ON DAY 8...AND 30 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 ABOVE AVERAGE... 4 ON A SCALE OF 1 TO 5 DUE TO EXCELLENT AGREEMENT AMONG THE ENSEMBLE MEAN MODEL SOLUTIONS AND GOOD CONTINUITY BUT SLIGHT DISAGREEMENT AMONG THE PRECIPITATION TOOLS. THE 6-10 DAY TEMPERATURE PROG IS BASED ON THE CPC AUTO FORECAST... THE CDC REFORECAST... ANALOGS OF THE OFFICIAL BLEND AND VARIOUS MODELS... TELECONNECTIONS ON A NEGATIVE 500-HPA HEIGHT ANOMALY CENTERED OVER NORTHERN GULF OF ALASKA... AND THE NORTH AMERICAN ENSEMBLE FORECAST SYSTEM TEMPERATURE GUIDANCE. THE 6-10 DAY PRECIPITATION PROG IS BASED ON THE CPC AUTO FORECAST... THE CDC REFORECAST... ANALOGS OF THE OFFICIAL BLEND AND VARIOUS MODELS... TELECONNECTIONS ON A NEGATIVE 500-HPA HEIGHT ANOMALY CENTERED OVER THE NORTHERN GULF OF ALASKA... AND THE CPC CALIBRATED PRECIPITATION FROM THE HIGH RESOLUTION GFS MODELS. 8-14 DAY OUTLOOK FOR DEC 29, 2007 - JAN 04, 2008: THE GFS ENSEMBLE MEAN SOLUTIONS ALONG WITH THE OPERATIONAL 0Z AND 6Z GFS MODEL RUNS AGREE THAT THE 500-HPA FLOW PATTERN BECOMES MORE ZONAL DURING THE WEEK 2 PERIOD. DURING THE PAST SEVERAL DAYS... GFS ENSEMBLE MEAN SOLUTIONS HAVE MAINTAINED A DOMINANT NEGATIVE 500-HPA HEIGHT ANOMALY (300 METERS ACCORDING TO THE OFFICIAL BLENDED HEIGHT FIELD) CENTERED OVER THE GULF OF ALASKA. TELECONNECTIONS ON THIS NEGATIVE HEIGHT ANOMALY CENTER SUPPORT A MILD TEMPERATURE PATTERN FOR THE CONUS AND A HIGH LIKELIHOOD OF ABOVE NORMAL PRECIPITATION FOR THE PACIFIC NORTHWEST AND NORTHERN CALIFORNIA. TEMPERATURES ARE FORECAST TO BE ABOVE NORMAL FOR MUCH OF THE CONUS EXCEPT FOR SOUTHERN CALIFORNIA AND THE DESERT SOUTHWEST WHERE BELOW NORMAL TEMPERATURES ARE FORECAST. BELOW NORMAL TEMPERATURES WILL LIKELY CONTINUE FOR MUCH OF ALASKA. WITH A PERSISTENT TROUGH CENTERED OVER THE GULF OF ALASKA... ABOVE NORMAL PRECIPITATION WILL LIKELY CONTINUE FOR THE THE PACIFIC NORTHWEST... NORTHERN CALIFORNIA... AND THE GREAT BASIN. LITTLE OR NO CHANGE IS ANTICIPATED IN THE STORM TRACK ACROSS THE CENTRAL AND EASTERN CONUS. THEREFORE... ABOVE NORMAL PRECIPITATION IS FORECAST FROM THE OHIO VALLEY INTO THE NORTHEAST. BELOW NORMAL PRECIPITATION IS EXPECTED ACROSS THE SOUTHEAST AND NORTHERN PLAINS. NEAR TO BELOW NORMAL PRECIPITATION IS FORECAST ACROSS ALASKA. THE OFFICIAL 8-14 DAY HEIGHT PROG CONSISTS OF 20 PERCENT OF TODAY'S OPERATIONAL 0Z GFS CENTERED ON DAY 11...20 PERCENT OF TODAY'S OPERATIONAL 6Z GFS CENTERED ON DAY 11...20 PERCENT OF TODAY'S 0Z GFS ENSEMBLE MEAN CENTERED ON DAY 11...20 PERCENT OF TODAY'S 6Z GFS ENSEMBLE MEAN CENTERED ON DAY 11...AND 20 PERCENT OF TODAY'S GFS SUPERENSEMBLE MEAN CENTERED ON DAY 11. FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD IS ABOVE AVERAGE... 4 DUE TO GOOD AGREEMENT AMONG THE MODELS AND GOOD CONTINUITY. THE 8-14 DAY TEMPERATURE PROG IS BASED ON THE CPC AUTO FORECAST... THE CDC REFORECAST... ANALOGS OF THE OFFICIAL BLEND AND VARIOUS MODELS... TELECONNECTIONS ON A NEGATIVE 500-HPA HEIGHT ANOMALY CENTERED OVER THE NORTHERN GULF OF ALASKA... 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... ANALOGS OF THE OFFICIAL BLEND AND VARIOUS MODELS... THE CPC CALIBRATED PRECIPITATION FROM THE HIGH RESOLUTION GFS MODELS... AND TELECONNECTIONS ON A NEGATIVE 500-HPA HEIGHT ANOMALY CENTERED OVER THE NORTHERN GULF OF ALASKA. FORECASTER: PUGH 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: 19571218 - 19750104 - 19571224 - 19961205 - 19671202 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: 19571217 - 19881221 - 19571224 - 19671201 - 19681202 6 to 10 day Outlook Table OUTLOOK FOR DEC 27 - 31, 2007 STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN WASHINGTON N A OREGON B A NRN CALIF B A SRN CALIF B A IDAHO B A NEVADA B A W MONTANA N A E MONTANA N B WYOMING B A UTAH B A ARIZONA B A COLORADO B A NEW MEXICO B A N DAKOTA N B S DAKOTA N B NEBRASKA A N KANSAS A A OKLAHOMA A A N TEXAS A A S TEXAS A A W TEXAS N A MINNESOTA A B IOWA A N MISSOURI A A ARKANSAS A A LOUISIANA A A WISCONSIN A N ILLINOIS A A MISSISSIPPI A A MICHIGAN A A INDIANA A A OHIO A A KENTUCKY A A TENNESSEE A A ALABAMA A A 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 A VIRGINIA A A N CAROLINA A N S CAROLINA A N GEORGIA A A FL PNHDL A B FL PENIN A B AK N SLOPE N N AK ALEUTIAN B A AK WESTERN B A AK INT BSN N N AK S INT N N AK SO COAST N N AK PNHDL N A 8 to 14 day Outlook Table OUTLOOK FOR DEC 29, 2007 - JAN 04, 2008 STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN WASHINGTON N A OREGON N A NRN CALIF N A SRN CALIF B N IDAHO A A NEVADA N A W MONTANA A N E MONTANA A B WYOMING A N UTAH N N ARIZONA N N COLORADO A N NEW MEXICO A N N DAKOTA A B S DAKOTA A B NEBRASKA A N KANSAS A A OKLAHOMA A A N TEXAS A N S TEXAS A N W TEXAS A N MINNESOTA A B IOWA A A MISSOURI A A ARKANSAS A A LOUISIANA A N WISCONSIN A N ILLINOIS A A MISSISSIPPI A B MICHIGAN A A INDIANA A A OHIO A A KENTUCKY A A TENNESSEE A N ALABAMA A B 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 B S CAROLINA A B GEORGIA A B FL PNHDL A B FL PENIN N B AK N SLOPE B B AK ALEUTIAN B N AK WESTERN B N AK INT BSN B B AK S INT B N AK SO COAST B 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. $$