PROGNOSTIC DISCUSSIONS FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS NWS CLIMATE PREDICTION CENTER CAMP SPRINGS MD 300 PM EDT THU APR 20 2006 6-10 DAY OUTLOOK VALID FOR APR 26 - 30 2006 TODAYS GFS AND ECMWF ENSEMBLE MEAN FORECASTS ARE IN FAIRLY GOOD AGREEMENT IN DEPICTING THE DEVELOPMENT OF A SPLIT-FLOW 500-HPA PATTERN OVER NORTH AMERICA. AN AMPLFIED NORTHERN STREAM IS PREDICTED WITH DEEP TROUGHS CENTERED NORTHEAST OF HUDSON BAY AND OVER NORTHWEST ALASKA AND A STRONG RIDGE OVER WEST/CENTRAL CANADA. A ZONALLY ORIENTED SOUTHERN JETSTREAM IS FORECAST TO DOMINATE THE SOUTHERN TIER STATES OF THE CONUS. THE CANADIAN ENSEMBLE MEAN IS LESS AMPLIFED WITH THE OVERALL CIRCULATION PATTERN AND MORE PROGRESSIVE WITH THE HUDSON BAY TROUGH. THE 0Z AND 6Z OPERATIONAL GFS ARE SIMILAR TO THE GFS ENSEMBLE MEAN SOLUTIONS ALTHOUGH THE 6Z OPERATIONAL GFS DEPICTS A VIGORIOUS SHORTWAVE MOVING OVER THE NORTHERN PLAINS THAT IS NOT INDICATED BY ANY OF THE OTHER MODEL SOLUTIONS. RECENT RUNS OF THE OPERATIONAL ECMWF ARE IN FAIRLY GOOD AGREEMENT WITH THE ECMWF ENSEMBLE MEAN SOLUTION ALTHOUGH THE MAIN CIRCULATION FEATURES ARE MORE AMPLIFIED IN THE OPERATIONAL RUNS. HEIGHTS OVER THE CONUS ARE GENERALLY EXPECTED TO BE NEAR OR ABOVE NORMAL EXCEPT OVER THE NORTHEAST STATES WHERE BELOW NORMAL HEIGHTS ARE FORECAST. THE CANADIAN ENSEMBLE MEAN DEPCITS HIGHER HEIGHTS OVER NEW ENGLAND COMPARED TO THE OTHER MODEL SOLUTIONS. HEIGHTS OVER ALASKA ARE PREDICTED TO BE BELOW NORMAL. THE MODELS SHOW FAIRLY GOOD CONTINUITY WITH RESPECT TO THEIR SOLUTIONS FROM YESTERDAY ALTHOUGH THE OPERATIONAL 6Z GFS TODAY DEPICTS MUCH LOWER HEIGHTS OVER THE NORTHERN ROCKIES. THE NAO INDEX WHICH RECENTLY HAS BEEN CLOSE TO ZERO IS FORECAST TO BE POSITIVE BY DAY 7... BE NEAR ZERO BY DAY 10 AND REMAIN NEAR ZERO THROUGH DAY 14. THE PNA INDEX HAS RECENTLY BEEN WEAKLY POSITIVE AND IS FORECAST TO BE WEAKLY TO MODERATELY POSITIVE FOR THE NEXT TWO WEEKS. THE ECMWF ENSEMBLE SPAGHETTI DIAGRAMS INDICATE MOSTLY LOW SPREAD... THE GFS ENSEMBLE SPAGHETTI DIAGRAMS ALSO INDICATE LOW SPREAD FOR MOST OF THE FORECAST DOMAIN WITH MODERATE SPREAD DEPICTED IN THE SOUTHERN STREAM WITH RESPECT TO HOW MUCH SHORTWAVE ENERGY MOVES INLAND OVER THE SOUTHWEST CONUS. THE CANADIAN ENSEMBLE SPAGHETTI DIAGRAMS INDICATE MODERATE TO LARGE SPREAD OVER MOST OF THE FORECAST DOMAIN. TEMPERATURES ACROSS MOST OF THE WESTERN TWO THIRDS OF THE CONUS ARE FORECAST TO BE NEAR OR ABOVE NORMAL UNDER THE INFLUENCE OF THE CENTRAL U.S. RIDGE AND ASSOCIATED AREA OF ABOVE NORMAL HEIGHTS. NEAR TO BELOW NORMAL TEMPERATURES ARE EXPECTED OVER THE EASTERN THIRD OF THE COUNTRY...THE GULF COAST AND MOST OF ALASKA DUE TO THE TROUGHS AND AREAS OF BELOW NORMAL HEIGHTS FORECAST THERE. PRECIPITATION ACROSS THE NORTHERN TIER STATES AND MUCH OF THE WESTERN CONUS IS FORECAST TO BE BELOW NORMAL DUE TO SUBSIDENCE ASSOCIATED WITH THE CENTRAL U.S. RIDGE... WHILE ABOVE NORMAL PRECIPITATION IS ANTICIPATED ALONG THE EAST COAST AND THE EASTERN TWO THIRDS OF ALASKA. THE AREAS THAT HAVE ELEVATED PROBABILITIES OF ABOVE NORMAL PRECIPITATION MOSTLY COINCIDE WITH AREAS OF ELEVATED PROBABILITIES OF BELOW NORMAL TEMPERATURES WHICH IS A CONSISTENT RELATIONSHIP IN THE SPRING. TODAYS OFFICIAL 500-HPA BLEND CONSISTS OF 10 PERCENT OF TODAY'S OPERATIONAL 0Z GFS CENTERED ON DAY 8...15 PERCENT OF TODAY'S OPERATIONAL ECMWF CENTERED ON DAY 7...15 PERCENT OF TODAY'S 0Z GFS ENSEMBLE MEAN CENTERED ON DAY 8...15 PERCENT OF TODAY'S 6Z GFS ENSEMBLE MEAN CENTERED ON DAY 8...20 PERCENT OF TODAY'S GFS SUPERENSEMBLE MEAN CENTERED ON DAY 8...AND 25 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 TODAY... 4 ON A SCALE OF 1 TO 5... DUE TO GOOD MODEL AGREEMENT. THE 6-10 DAY TEMPERATURE PROG IS BASED ON THE KLEIN... ANALOG... AND NEURAL NETWORK SPECIFICATIONS FROM THE OFFICIAL BLEND... THE CPC AUTO TEMPERATURE FORECAST... KLEIN AND NEURAL NETWORK PROBABILITIES FROM THE GFS AND ECMWF ENSEMBLES... CALIBRATED AND UNCALIBRATED 2 METER TEMPERATURES FROM THE 0Z AND 6Z GFS ENSEMBLE MEMBERS... CDC CALIBRATED TEMPERATURE PROBABILITIES AND THE BIAS CORRECTED 850-HPA TEMPERATURES FROM THE 0Z OPERATIONAL GFS. THE 6-10 DAY PRECIPITATION PROG IS BASED ON THE ANALOG AND NEURAL NET SPECIFICATIONS FROM THE OFFICIAL BLEND AND THE INDIVIDUAL FORECAST MODELS... THE CPC AUTO PRECIPITATION FORECAST... EMC AND CPC CALIBRATED PRECIPITATION PERCENTAGES FROM THE GFS ENSEMBLES... CDC CALIBRATED PRECIPITATION PROBABILITIES AND CALIBRATED PRECIPITATION FROM THE 0Z OPERATIONAL GFS AND 0Z GFS ENSEMBLE MEAN. 8-14 DAY OUTLOOK FOR APR 28 - MAY 04, 2006: DURING WEEK 2 THE GFS SUPERENSEMBLE MEAN PREDICTS THE 500-HPA FLOW PATTERN TO BE DEAMPLIFIED AND SLIGHTLY PROGRESSIVE FROM THAT DEPICTED DURING THE 6-10 DAY PERIOD. AS A RESULT MOST OF THE CONUS IS FORECAST TO BE DOMINATED BY FAST ZONAL FLOW WITH WEAK RIDGING DEPICTED OVER THE NORTH/CENTRAL CONUS. THE 0Z AND 6Z OPERATIONAL GFS ARE A BIT MORE AMPLIFIED WITH THE PATTERN COMPARED TO THE GFS SUPERENSEMBLE MEAN AND ALSO DISPLAY SOME TIMING DIFFERENCES WITH INDIVIDUAL CIRCULATION FEATURES. THE MODELS ARE IN FAIRLY GOOD AGREEMENT THAT A TROUGH WILL DOMINATE WESTERN ALASKA WHILE A RIDGE IS FORECAST TO BUILD OVER FAR EASTERN ALASKA. HEIGHTS ARE GENERALLY FORECAST TO BE NEAR TO ABOVE NORMAL OVER MOST OF THE CONUS ALTHOUGH NEAR TO BELOW NORMAL HEIGHTS ARE INDICATED ACROSS THE SOUTHERN TIER STATES. ALASKA IS FORECAST TO HAVE BELOW NORMAL HEIGHTS. THE ENSEMBLE MEAN SOLUTIONS SHOW FAIRLY GOOD CONTINUITY WITH RESPECT TO THEIR SOLUTIONS FROM YESTERDAY ALTHOUGH TODAYS SOLUTIONS ARE SOMEWHAT LESS AMPLIFIED. THE 0Z AND 6Z OPERATIONAL GFS SHOW FAIR CONTINUITY WITH A TENDENCY TO PREDICT LOWER HEIGHTS OVER THE SOUTHWESTERN CONUS IN TODAYS RUNS. THE ENSEMBLE SPAGHETTI DIAGRAMS INDICATE MODERATE TO LARGE SPREAD TODAY ACROSS MOST OF THE CONUS AND LARGE SPREAD OVER THE NORTHEAST ATLANTIC AND EASTERN PACIFIC. THE FORECAST TEMPERATURE AND PRECIPITATION PATTERNS FOR WEEK 2 ARE VERY SIMILAR TO THAT FORECAST FOR THE 6-10 DAY PERIOD ALTHOUGH THE ANOMALY PATTERNS DURING WEEK 2 ARE SHIFTED A BIT TO THE EAST COMPARED TO THE 6-10 DAY PERIOD. THE OFFICIAL 8-14 DAY HEIGHT PROG CONSISTS OF 10 PERCENT OF TODAY'S OPERATIONAL 0Z GFS CENTERED ON DAY 11...5 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 45 PERCENT OF TODAY'S GFS SUPERENSEMBLE 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 OFFSET BY RELATIVELY LARGE SPREAD AMONG THE ENSEMBLE MEMBERS. THE 8-14 DAY TEMPERATURE PROG IS BASED ON THE KLEIN... NEURAL NET... AND ANALOG SPECIFICATIONS FROM THE OFFICIAL BLEND... THE CPC AUTO TEMPERATURE FORECAST... KLEIN PROBABILITIES FROM THE GFS ENSEMBLE MEMBERS... UNCALIBRATED AND CALIBRATED 2 METER TEMPERATURES FROM THE 0Z AND 6Z GFS ENSEMBLE MEMBERS... CDC CALIBRATED TEMPERATURE PROBABILITIES... AND THE BIAS-CORRECTED 850-HPA TEMPERATURES FROM THE 0Z OPERATIONAL GFS. THE 8-14 DAY PRECIPITATION PROG IS BASED ON THE ANALOG AND NEURAL NET SPECIFICATIONS FROM THE OFFICIAL BLEND... ANALOG SPECIFICATIONS FROM THE GFS ENSEMBLE MEANS... CPC CALIBRATED PRECIPITATION PERCENTAGES FROM THE GFS ENSEMBLE MEMBERS... CDC CALIBRATED PRECIPITATION PROBABILITIES... AND CALIBRATED PRECIPITATION FROM THE 0Z GFS OPERATIONAL AND 0Z ENSEMBLE MEAN FORECASTS. FORECASTER: R. SCHECHTER 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 18. AN UPDATED MONTHLY FORECAST FOR MAY WILL BE ISSUED ON APRIL 30. 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: 19640430 - 19710418 - 19840410 - 19550425 - 19520430 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: 19640429 - 19750425 - 19710418 - 19520331 - 19550425 6 to 10 day Outlook Table OUTLOOK FOR APR 26 - 30, 2006 STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN WASHINGTON A B OREGON A B NRN CALIF N N SRN CALIF A N IDAHO A B NEVADA A B W MONTANA A B E MONTANA A B WYOMING A N UTAH A N ARIZONA A N COLORADO N N NEW MEXICO N N N DAKOTA A B S DAKOTA A B NEBRASKA N B KANSAS N B OKLAHOMA N B N TEXAS B B S TEXAS B N W TEXAS N B MINNESOTA N B IOWA N B MISSOURI N B ARKANSAS N B LOUISIANA B N WISCONSIN N B ILLINOIS N B MISSISSIPPI N N MICHIGAN N B INDIANA B B OHIO B N KENTUCKY N N TENNESSEE N N ALABAMA B 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 N MARYLAND B A DELAWARE B A VIRGINIA B A N CAROLINA N A S CAROLINA N A GEORGIA B A FL PNHDL B A FL PENIN B N AK N SLOPE B A AK ALEUTIAN B N AK WESTERN B N AK INT BSN B A AK S INT B A AK SO COAST B A AK PNHDL N A 8 to 14 day Outlook Table OUTLOOK FOR APR 28 - MAY 04, 2006 STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN WASHINGTON A B OREGON A B NRN CALIF A B SRN CALIF N N IDAHO A N NEVADA A N W MONTANA A B E MONTANA A B WYOMING A N UTAH A N ARIZONA A N COLORADO A A NEW MEXICO A A N DAKOTA A B S DAKOTA A B NEBRASKA A N KANSAS A N OKLAHOMA N N N TEXAS N N S TEXAS B B W TEXAS N A MINNESOTA A B IOWA A N MISSOURI A N ARKANSAS N N LOUISIANA N B WISCONSIN A B ILLINOIS A B MISSISSIPPI N B MICHIGAN A B INDIANA A B OHIO N B KENTUCKY N B TENNESSEE N B ALABAMA N B NEW YORK N B VERMONT N B NEW HAMP B B MAINE B N MASS B B CONN B B RHODE IS B B PENN N B NEW JERSEY B B W VIRGINIA N B MARYLAND N B DELAWARE B B VIRGINIA N B N CAROLINA B B S CAROLINA B B GEORGIA N B FL PNHDL N B FL PENIN B B AK N SLOPE B N AK ALEUTIAN B N AK WESTERN B B AK INT BSN B A AK S INT B A AK SO COAST B A AK PNHDL B 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. $$