PROGNOSTIC DISCUSSIONS FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS NWS CLIMATE PREDICTION CENTER CAMP SPRINGS MD 300 PM EDT FRI MAY 02 2008 6-10 DAY OUTLOOK VALID FOR MAY 08 - 12 2008 TODAYS MODEL SOLUTIONS ARE IN RELATIVELY POOR AGREEMENT ON THE EXPECTED 500-HPA FLOW PATTERN OVER NORTH AMERICA FOR THE 6-10 DAY PERIOD. THE ENSEMBLE MEANS FROM THE ECMWF, CANADIAN, AND 0Z GFS MODELS DEPICT TROUGHS OVER WESTERN ALASKA AND EASTERN CANADA. RIDGES ARE FORECAST OVER THE EASTERN PACIFIC OCEAN, WESTERN CANADA, AND CENTRAL MEXICO. THE ECMWF ENSEMBLE MEAN AND OPERATIONAL ECMWF SOLUTIONS ARE THE MOST PROGRESSIVE IN DEPICTING A BROAD TROUGH OVER THE INTERMOUNTAIN WEST AND NORTH-CENTRAL U.S. WHILE THE 0Z GFS AND CANADIAN ENSEMBLE MEANS KEEP THIS FEATURE ALONG THE WEST COAST. THE CANADIAN AND 0Z GFS ENSEMBLE MEANS DEPICT A STRONGER EASTERN CANADIAN TROUGH RELATIVE TO THE ECMWF MEAN. FURTHER UPSTREAM, THE ECMWF SOLUTIONS ARE THE STRONGEST AND MOST PROGRESSIVE WITH THE EASTERN PACIFIC RIDGE WHILE THE CANDIAN MEAN IS THE WEAKEST WITH THIS FEATURE. TODAYS GFS OPERATIONAL RUNS SHOW VERY LITTLE CONSISTENCY WITH EACH OTHER AND WERE DISCOUNTED. DUE TO SUPERIOR 500-HPA ANOMALY CORRELATION SCORES DURING THE PAST 60 DAYS, THE ECMWF ENSEMBLE MEAN WAS WEIGHTED THE MOST HEAVILY IN TODAYS OFFICIAL 500-HPA BLEND. THIS BLEND CHART INDICATES NEAR TO ABOVE NORMAL HEIGHTS OVER THE WESTERN THIRD OF THE CONUS. NEAR TO BELOW NORMAL HEIGHTS ARE FORECAST ACROSS THE EASTERN TWO-THIRDS OF THE CONUS AND SOUTHWEST ALASKA. SHORTWAVE ENERGY EJECTING NORTHEASTWARD FROM THE TROUGH OVER THE INTERMOUNTAIN WEST SHOULD LEAD TO WETTER THAN NORMAL CONDITIONS FOR MUCH OF THE GREAT LAKES REGION AND THE NORTHEAST. MOIST FLOW FROM THE GULF AHEAD OF THIS FEATURE ALSO FAVORS ABOVE NORMAL PRECIPITATION FOR MUCH OF THE SOUTHEAST. A SECOND AREA OF ABOVE NORMAL PRECIPITATION IS LIKELY FOR PARTS OF THE EASTERN ROCKIES CLOSER TO THE TROUGH ITSELF POSSIBLY AIDED BY UPSLOPE FLOW. SOUTHWESTERLY MID-LEVEL FLOW AHEAD OF THE WESTERN ALASKA TROUGH SHOULD LEAD TO ABOVE NORMAL PRECIPITATION FOR MUCH OF THE SOUTH COAST. COOLER THAN NORMAL WEATHER IS LIKELY OVER MUCH OF THE NORTH-CENTRAL CONUS EXTENDING TO THE NORTHEAST DUE TO NEAR TO BELOW NORMAL 500-HPA HEIGHTS. ABOVE NORMAL TEMPERATURES ARE LIKELY TO THE SOUTH OF THE MEAN STORM TRACK FOR THE WESTERN GULF COAST REGION. ABOVE NORMAL TEMPERATURES ARE ALSO LIKELY FOR MUCH OF THE SOUTHWEST CONUS UNDERNEATH NEAR TO ABOVE NORMAL 500-HPA HEIGHTS. HOWEVER, BELOW NORMAL SEA SURFACE TEMPERATURES OFF THE CALIFORNIA COAST LIKELY WILL KEEP THE ABOVE NORMAL TEMPERATURES AWAY FROM THE IMMEDIATE COASTLINE. TODAYS OFFICIAL 500-HPA BLEND CONSISTS OF 10 PERCENT OF TODAY'S OPERATIONAL ECMWF CENTERED ON DAY 7...25 PERCENT OF TODAY'S 0Z GFS ENSEMBLE MEAN CENTERED ON DAY 8...30 PERCENT OF TODAY'S CANADIAN ENSEMBLE MEAN CENTERED ON DAY 8...AND 35 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 BELOW AVERAGE... 2 ON A SCALE OF 1 TO 5 DUE TO HIGH SPREAD AMONG THE ENSEMBLE MEMBERS FROM THE ECMWF... CANADIAN... AND GFS MODEL RUNS. THE 6-10 DAY TEMPERATURE PROG IS BASED ON THE KLEIN AND ANALOG SPECIFICATIONS FROM THE BLENDED HEIGHT FIELD, THE NORTH AMERICAN ENSEMBLE FORECAST SYSTEM TEMPERATURE FORECAST, AND TELECONNECTIONS FROM POSITIVE HEIGHT ANOMALIES CENTERED AT 67N, 50W AND 44N,138W. THE 6-10 DAY PRECIPITATION PROG IS BASED ON THE NEURAL NET AND ANALOG SPECIFICATIONS FROM THE OFFICIAL BLEND AND TELECONNECTIONS FROM POSITIVE HEIGHT ANOMALIES CENTERED AT 67N, 50W AND 44N,138W. 8-14 DAY OUTLOOK FOR MAY 10 - 16 2008: FOR WEEK 2 THE 0Z GFS GFS AND CANADIAN ENSEMBLE MEANS INDICATE TROUGHS OVER THE BERING SEA, THE WEST COAST, AND THE EASTERN THIRD OF THE CONUS. RIDGES ARE FORECAST OVER THE EASTERN PACIFIC OCEAN, WESTERN CANADA, AND SOUTHERN GREENLAND. HIGH SPREAD AND LOW RUN TO RUN CONSISTENCY HAS PREVENTED PLACING ANY WEIGHT ON ANY INDIVIDUAL GFS OPERATIONAL RUN. THUS TODAYS WEEK 2 FORECAST WAS BASED ENTIRELY ON THE ENSEMBLE MEANS (PARTICULARLY THE CANADIAN MEAN WHICH HAS SHOWN HIGHER SKILL RECENTLY RELATIVE TO THE GFS ENSEMBLE MEANS). THE 500-HPA BLEND CHART SHOWS BELOW NORMAL HEIGHTS OVER MOST OF THE EASTERN TWO-THIRDS OF THE CONUS AND WESTERN ALASKA. ABOVE NORMAL HEIGHTS ARE DEPICTED OVER THE WESTERN THIRD OF THE CONUS AND OVER GREENLAND AND MUCH OF NORTHERN CANADA CENTERED NEAR BAFFIN BAY. THE POSITIVE HEIGHT ANOMALIES CENTERED NEAR BAFFIN BAY ARE PARTICULARLY STRONG AND ARE ASSOCIATED WITH THE RIDGE OVER SOUTHERN GREENLAND. TELECONNECTIONS FROM THIS ANOMALY CENTER SUPPORT THE TROUGH OVER THE EASTERN THIRD OF THE CONUS. THIS TROUGH IS EXPECTED TO BRING COOLER THAN NORMAL CONDITIONS FOR MUCH OF THE GREAT LAKES/NORTHEAST AND WETTER THAN NORMAL CONDITIONS FOR MUCH OF THE EAST COAST. FURTHER TO THE WEST, WARMER THAN NORMAL CONDITIONS ARE EXPECTED FOR MUCH OF THE WESTERN THIRD OF THE CONUS UNDERNEATH ABOVE NORMAL HEIGHTS. ELSEWHERE, THE WEEK 2 TEMPERATURE AND PRECIPITATION FORECASTS ARE FAIRLY SIMILAR TO THE 6 TO 10 DAY PROGS. THE OFFICIAL 8-14 DAY HEIGHT PROG CONSISTS OF 35 PERCENT OF TODAY'S 0Z GFS ENSEMBLE MEAN CENTERED ON DAY 11...AND 65 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 HIGH SPREAD AMONG THE GFS AND CANADIAN 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 TEMPERATURES, AND TELECONNECTIONS FROM A POSITIVE HEIGHT ANOMALY CENTERED AT 67N, 63W. THE 8-14 DAY PRECIPITATION PROG IS BASED ON THE ANALOG AND NEURAL NET SPECIFICATIONS FROM THE OFFICIAL BLEND AND TELECONNECTIONS FROM POSITIVE HEIGHT ANOMALIES CENTERED AT 67N, 63W. FORECASTER: HANDEL 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 16. 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: 19500422 - 19730427 - 19960429 - 19610416 - 19840503 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: 19960429 - 19500422 - 19730426 - 19610415 - 19620411 6 to 10 day Outlook Table OUTLOOK FOR MAY 08 - 12, 2008 STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN WASHINGTON N B OREGON N B NRN CALIF N B SRN CALIF A N IDAHO N N NEVADA A N W MONTANA B N E MONTANA B N WYOMING N A UTAH N N ARIZONA A N COLORADO N A NEW MEXICO N B N DAKOTA B N S DAKOTA B N NEBRASKA N N KANSAS N N OKLAHOMA N N N TEXAS A N S TEXAS A N W TEXAS N B MINNESOTA B N IOWA B N MISSOURI N N ARKANSAS N N LOUISIANA A N WISCONSIN B N ILLINOIS B N MISSISSIPPI A N MICHIGAN B A INDIANA B A OHIO B A KENTUCKY N N TENNESSEE N A ALABAMA N A NEW YORK B A VERMONT B A NEW HAMP B A MAINE N A MASS B A CONN B A RHODE IS B A PENN B A NEW JERSEY B A W VIRGINIA B A MARYLAND B A DELAWARE B A VIRGINIA B A N CAROLINA N A S CAROLINA N A GEORGIA N A FL PNHDL N A FL PENIN N N AK N SLOPE A B AK ALEUTIAN B N AK WESTERN B N AK INT BSN N B AK S INT B A AK SO COAST B A AK PNHDL N A 8 to 14 day Outlook Table OUTLOOK FOR MAY 10 - 16, 2008 STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN WASHINGTON A B OREGON A B NRN CALIF A B SRN CALIF A N IDAHO N N NEVADA A N W MONTANA N N E MONTANA N N WYOMING N A UTAH N N ARIZONA A N COLORADO N A NEW MEXICO N N N DAKOTA B N S DAKOTA B N NEBRASKA N N KANSAS N N OKLAHOMA N N N TEXAS N N S TEXAS N B W TEXAS N N MINNESOTA B N IOWA B N MISSOURI N N ARKANSAS N N LOUISIANA N N WISCONSIN B N ILLINOIS B N MISSISSIPPI N N MICHIGAN B N INDIANA B N OHIO B N KENTUCKY B N TENNESSEE B N ALABAMA N N NEW YORK B A VERMONT B A NEW HAMP B A MAINE B A MASS B A CONN B A RHODE IS B A PENN B A NEW JERSEY B A W VIRGINIA B A MARYLAND B A DELAWARE B A VIRGINIA B A N CAROLINA N A S CAROLINA N A GEORGIA N A FL PNHDL N A FL PENIN N A AK N SLOPE A N AK ALEUTIAN B N AK WESTERN B N AK INT BSN A N AK S INT N A AK SO COAST B A AK PNHDL N 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. $$