PROGNOSTIC DISCUSSIONS FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS NWS CLIMATE PREDICTION CENTER CAMP SPRINGS MD 300 PM EDT WED MAY 17 2006 6-10 DAY OUTLOOK VALID FOR MAY 23 - 27 2006 THE ENSEMBLE MEANS FROM THE GFS AND ECMWF ARE IN REASONABLY GOOD AGREEMENT ON THE PREDICTED 6 TO 10 DAY MEAN 500-HPA FLOW PATTERN OVER NORTH AMERICA... AS A GRADUAL DEAMPLIFICATION AND MORE PROGRESSIVE FLOW EVOLVES. THE GFS AND ECMWF MEAN 500-HPA SOLUTIONS DEPICT A TROUGH JUST OFF THE WEST COAST... A RIDGE CENTERED OVER THE PLAINS... AND A DOWNSTREAM TROUGH OVER THE WESTERN ATLANTIC. 0Z GFS ENSEMBLE MEMBERS REMAIN IN GOOD AGREEMENT EARLY IN THE PERIOD WITH MODERATE AMPLIFICATION TO THE 500-HPA FLOW BUT SPREAD INCREASES SIGNIFICANTLY AS THE PATTERN BECOMES LESS AMPLIFIED BY THE END OF THE PERIOD. THE DOMINANT RIDGE ALOFT CENTERED OVER THE PLAINS COULD LEAD TO WELL ABOVE NORMAL TEMPERATURES FOR THE CENTRAL AND SOUTHERN PLAINS. AS 500-HPA HEIGHTS RISE IN THE EAST... A WARMING TREND IS ANTICIPATED FOR THE MID-ATLANTIC AND SOUTHEAST. BELOW NORMAL TEMPERATURES SHOULD BE LIMITED TO NEW ENGLAND... THE PACIFIC NORTHWEST... NORTHERN CALIFORNIA... AND THE ALASKAN PANHANDLE. THE LARGE SCALE 500-HPA RIDGE WILL LIKELY SUPPRESS CONVECTION AND RESULT IN BELOW NORMAL PRECIPITATION FROM THE ROCKIES TO THE EAST COAST... BUT THE 500-HPA TROUGH OFF THE WEST COAST COULD BRING ABOVE NORMAL PRECIPITATION TO THE PACIFIC NORTHWEST AND NORTHERN CALIFORNIA. THE GREATEST UNCERTAINTY EXISTS ALONG THE NORTHER TIER OF THE CONUS WHERE SOME FORECAST TOOLS SUGGEST NEAR TO ABOVE NORMAL PRECIPITATION AS FLOW BECOMES MORE ZONAL. MEANWHILE... A MODERATELY STRONG 500-HPA RIDGE ACROSS THE ALEUTIANS SHOULD FAVOR BELOW NORMAL PRECIPITATION FOR THE ALEUTIANS AND SOUTHERN ALASKA. TODAYS OFFICIAL 500-HPA BLEND CONSISTS OF 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...50 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: GFS SUPERENSEMBLE MEAN. FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD IS ABOVE AVERAGE TODAY... 4 ON A SCALE OF 1 TO 5... DUE TO REASONABLY GOOD AGREEMENT AMONG THE MODELS AND TOOLS. THE 6-10 DAY TEMPERATURE PROG IS BASED ON THE KLEIN... NEURAL NET... AND ANALOG SPECIFICATIONS FROM THE OFFICIAL BLEND... THE CPC AUTO TEMPERATURE FORECAST... AND THE CDC REFORECAST TEMPERATURE TOOL. 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... THE CDC PRECIPITATION PROBABILITIES FROM THE REFORECAST TOOL... AND CPC CALIBRATED PRECIPITATION PERCENTAGES FOR THE GFS ENSEMBLE MEMBERS. 8-14 DAY OUTLOOK FOR MAY 25 - 31 2006: THE MEAN 500-HPA HEIGHT PATTERN PREDICTED BY THE GFS ENSEMBLES SUGGEST THAT A LESS AMPLIFIED FLOW PATTERN... MORE TYPICAL OF LATE SPRING... WILL PREVAIL DURING WEEK 2. THE OFFICIAL BLEND CHART SHOWS A BROAD 500-HPA RIDGE EXTENDING FROM THE PLAINS AND MIDDLE MISSISSIPPI VALLEY INTO THE MID-ATLANTIC... AND A WEAK 500-HPA TROUGH ALONG THE WEST COAST. 500-HPA HEIGHT ANOMALIES ARE RELAVTIVELY WEAK COMPARED TO PREVIOUS DAYS WITH THE GREATEST POSITIVE ANOMALIES ASSOCIATED WITH THE RIDGE OVER THE MIDDLE MISSISSIPPI VALLEY. TEMPERATURES MAY REMAIN BELOW NORMAL IN NORTHERN NEW ENGLAND BUT ABOVE NORMAL TEMPERATURES SHOULD PERSIST ACROSS THE PLAINS... OHIO VALLEY... AND SOUTH. NEAR TO BELOW NORMAL TEMPERATURES ARE EXPECTED FOR THE PACIFIC NORTHWEST WITH ABOVE NORMAL TEMPERATURES ACROSS MUCH OF ALASKA. DESPITE A WEAKENING TREND IN THE 500-HPA RIDGE... BELOW NORMAL PRECIPITATION SHOULD PERSIST FROM THE SOUTHERN PLAINS INTO THE OHIO VALLEY AND MID-ATLANTIC. THE GFS SUPERENSEMBLE CALIBRATED PRECIPITATION PERCENTAGES SUGGEST THAT THE FLORIDA PENINSULA MAY EXPERIENCE ABOVE NORMAL PRECIPITATION... LIKELY DUE TO LESS INFLUENCE FROM THE WEAKENING 500-HPA RIDGE. A MORE ZONAL FLOW PATTERN MAY PROMOTE INCREASED STORMINESS ALONG THE US-CANADIAN BORDER WITH ABOVE NORMAL PRECIPITATION BECOMING MORE LIKELY FOR THE UPPER MISSISSIPPI VALLEY. THE WEAK TROUGH ALONG THE WEST COAST MAY PROLONG THE WETTER-THAN-NORMAL CONDITIONS IN THE PACIFIC NORTHWEST. ELSEWHERE... BELOW NORMAL PRECIPITATION IS EXPECTED FOR MUCH OF ALASKA. THE OFFICIAL 8-14 DAY HEIGHT PROG CONSISTS OF 25 PERCENT OF TODAY'S 0Z GFS ENSEMBLE MEAN CENTERED ON DAY 11...25 PERCENT OF TODAY'S 6Z GFS ENSEMBLE MEAN CENTERED ON DAY 11...AND 50 PERCENT OF TODAY'S GFS SUPERENSEMBLE MEAN CENTERED ON DAY 11. FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD IS AVERAGE... 3 ON A SCALE OF 1 TO 5... DUE TO GOOD AGREEMENT AMONG THE MODEL GUIDANCE AND TOOLS BUT OFFSET BY A MORE ZONAL FLOW PATTERN. 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... AND CDC PROBABILITIES FROM THE GFS REFORECAST TOOL. THE 8-14 DAY PRECIPITATION PROG IS BASED ON THE ANALOG AND NEURAL NET SPECIFICATIONS FROM THE OFFICIAL BLEND... CPC CALIBRATED PRECIPITATION PERCENTAGES FOR THE GFS ENSEMBLE MEMBERS... AND CDC PROBABILITIES FROM THE GFS REFORECAST PRECIPITATION TOOL. 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 MAY 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: 19600510 - 19520511 - 19540510 - 19720527 - 19860526 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: 19600510 - 19540509 - 19520511 - 19830528 - 19860525 6 to 10 day Outlook Table OUTLOOK FOR MAY 23 - 27, 2006 STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN WASHINGTON B A OREGON B A NRN CALIF B A SRN CALIF N N IDAHO N N NEVADA N N W MONTANA N N E MONTANA A N WYOMING A B UTAH A N ARIZONA A N COLORADO A B NEW MEXICO A B N DAKOTA A N S DAKOTA A B NEBRASKA A B KANSAS A B OKLAHOMA A B N TEXAS A B S TEXAS A N W TEXAS A B MINNESOTA A N IOWA A B MISSOURI A B ARKANSAS A B LOUISIANA A B WISCONSIN A N ILLINOIS A B MISSISSIPPI A B MICHIGAN N N INDIANA A B OHIO A B KENTUCKY A B TENNESSEE A B ALABAMA A B NEW YORK B N VERMONT B N NEW HAMP B N MAINE B N MASS B N CONN B B RHODE IS B B PENN N B NEW JERSEY N B W VIRGINIA A B MARYLAND N B DELAWARE N B VIRGINIA A B N CAROLINA A B S CAROLINA A B GEORGIA A B FL PNHDL A N FL PENIN A N AK N SLOPE A N AK ALEUTIAN N B AK WESTERN N N AK INT BSN N N AK S INT N B AK SO COAST N B AK PNHDL B N 8 to 14 day Outlook Table OUTLOOK FOR MAY 25 - 31, 2006 STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN WASHINGTON B A OREGON B A NRN CALIF N N SRN CALIF N N IDAHO B N NEVADA N N W MONTANA B A E MONTANA N N WYOMING A B UTAH A N ARIZONA A N COLORADO A B NEW MEXICO A B N DAKOTA N A S DAKOTA A N NEBRASKA A B KANSAS A B OKLAHOMA A B N TEXAS A B S TEXAS A N W TEXAS A B MINNESOTA N A IOWA A N MISSOURI A B ARKANSAS A B LOUISIANA A B WISCONSIN N A ILLINOIS A B MISSISSIPPI A B MICHIGAN N A INDIANA A N OHIO A B KENTUCKY A B TENNESSEE A B ALABAMA A B NEW YORK N B VERMONT B B NEW HAMP B B MAINE B B MASS B B CONN N B RHODE IS N B PENN A B NEW JERSEY N B W VIRGINIA A B MARYLAND A B DELAWARE A B VIRGINIA A B N CAROLINA A B S CAROLINA A B GEORGIA A B FL PNHDL A N FL PENIN A A AK N SLOPE A N AK ALEUTIAN N B AK WESTERN A B AK INT BSN A N AK S INT A B AK SO COAST A B AK PNHDL N B 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. $$