PROGNOSTIC DISCUSSIONS FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS NWS CLIMATE PREDICTION CENTER CAMP SPRINGS MD 300 PM EDT TUE MAY 20 2008 6-10 DAY OUTLOOK VALID FOR MAY 26 - 30 2008 THE ENSEMBLE MEAN SOLUTIONS REMAIN IN GOOD AGREEMENT ON THE EXPECTED 500-HPA LONGWAVE PATTERN THAT FEATURES AN AMPLIFIED TROUGH NEAR THE WEST COAST... A BROAD RIDGE CENTERED OVER THE WESTERN GULF COAST... AND A TROUGH OFFSHORE OF THE EAST COAST. ONE NOTABLE CHANGE SINCE YESTERDAYS MODEL RUNS IS A WEAKER RIDGE OVER THE MISSISSIPPI VALLEY DUE TO THE INFLUENCE OF A DEEP VORTEX NEAR HUDSON BAY. THE OPERATIONAL MODEL RUN OF THE 0Z ECMWF IS THE STRONGEST WITH THE COLD VORTEX IN EASTERN CANADA AND INDICATES BELOW NORMAL 500-HPA HEIGHTS INTO THE GREAT LAKES. THIS OPERATIONAL RUN OF THE 0Z ECMWF WAS USED IN THE OFFICIAL BLENDED 500-HPA HEIGHT FIELD AND WOULD SUPPORT BELOW NORMAL TEMPERATURES ACROSS THE NORTHERN PLAINS AND UPPER MISSISSIPPI VALLEY. AFTER THE RECENT RECORD HEAT IN SOUTHERN CALIFORNIA AND THE SOUTHWEST... RELIEF FROM THE HEAT IS EXPECTED WITH BELOW NORMAL TEMPERATURES FORECAST. HOWEVER.. HOT TEMPERATURES COULD RETURN BY THE END OF THE PERIOD. THE BROAD RIDGE SHOULD RESULT IN ABOVE NORMAL TEMPERATURES OVER THE SOUTHERN PLAINS INTO THE MIDDLE AND LOWER MISSISSIPPI VALLEY. A BRIEF PERIOD OF WARMER THAN NORMAL TEMPERATURES MAY SPREAD INTO PARTS OF THE EASTERN CONUS... BUT TEMPERATURES SHOULD AVERAGE NEAR NORMAL DURING THE 5-DAY PERIOD. ABOVE NORMAL 500-HPA HEIGHTS FAVOR ABOVE NORMAL TEMPERATURES ACROSS ALASKA. THE PRESENCE OF THE TROUGH NEAR THE WEST COAST COMBINED WITH AMPLE GULF MOISTURE WILL LIKELY LEAD TO WELL ABOVE NORMAL PRECIPITATION ACROSS THE PLAINS AND CORN BELT. THE OPERATIONAL MODEL RUNS OF THE 0Z AND 6Z GFS INDICATE THE POTENTIAL FOR SEVERAL INCHES OF RAINFALL IN THESE AREAS. ACROSS MUCH OF THE EAST COAST... RAINFALL AMOUNTS SHOULD AVERAGE NEAR OR BELOW NORMAL. TYPICALLY THE RAINY SEASON BEGINS IN SOUTH FLORIDA BY LATE MAY. OPERATIONAL GFS MODEL RUNS HAVE CONSISTENTLY SHOWN A BROAD AREA OF LOW PRESSURE DEVELOPING NEAR FLORIDA AND COULD BRING ABOVE NORMAL PRECIPITATION TO THE SOUTHERN THIRD OF THE PENINSULA. BELOW NORMAL PRECIPITATION IS FORECAST FOR EASTERN ALASKA AND THE ALASKAN PANHANDLE WITH SLIGHT ODDS TOWARDS ABOVE NORMAL PRECIPITATION IN WESTERN ALASKA. TODAYS OFFICIAL 500-HPA BLEND CONSISTS OF 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...20 PERCENT OF TODAY'S GFS SUPERENSEMBLE MEAN CENTERED ON DAY 8...AND 40 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 GOOD AGREEMENT AMONG THE ENSEMBLE MEAN SOLUTIONS. 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... KLEIN AND ANALOG SPECIFICATIONS FROM THE GFS AND ECMWF... AND THE CPC AUTO BLEND TEMPERATURE FORECAST. THE 6-10 DAY PRECIPITATION PROG IS BASED ON THE NEURAL NET AND ANALOG SPECIFICATIONS FROM THE OFFICIAL BLEND... ANALOG SPECIFICATIONS FROM THE GFS ENSEMBLES... THE CPC AUTO BLEND PRECIPITATION FORECAST... AND THE DAILY PRECIPITATION FORECASTS FROM THE GFS AND ECMWF MODELS. 8-14 DAY OUTLOOK FOR MAY 28 - JUN 03, 2008: FOR WEEK 2... THE GFS ENSEMBLE MEAN SOLUTIONS INDICATE THAT THE PAIR OF TROUGHS NEAR THE WEST AND EAST COASTS WILL WEAKEN WITH A PERSISTENT BROAD RIDGE OVER THE SOUTHERN CONUS. THE OFFICIAL BLENDED 500-HPA FIELD SHOWS HEIGHT ANOMALIES AT OR ABOVE NORMAL FOR MOST OF THE CONUS AND ALASKA. AS A RESULT... TEMPERATURES SHOULD AVERAGE AT OR ABOVE NORMAL FOR MOST AREAS. EARLY IN THE PERIOD... ACTIVE WEATHER SHOULD CONTINUE FOR THE NORTHERN HALF OF THE CONUS WITH ABOVE NORMAL PRECIPITATION MOST LIKELY AFFECTING THE NORTHERN AND CENTRAL PLAINS ALONG WITH THE MIDWEST. AFTER A WET PERIOD ACROSS PARTS OF THE WESTERN CONUS... A DRYING TREND IS EXPECTED AS 500-HPA HEIGHTS INCREASE WITH THE WEAKENING TROUGH. NEAR NORMAL PRECIPITATION IS FORECAST FOR THE NORTHEAST AND MID-ATLANTIC WITH BELOW NORMAL PRECIPITATION ACROSS PARTS OF THE SOUTHEAST. NEAR OR BELOW NORMAL PRECIPITATION IS EXPECTED ACROSS ALASKA WHERE ABOVE NORMAL 500-HPA HEIGHTS DOMINATE. 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 AN EXPECTED ZONAL FLOW PATTERN. 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 THE CPC AUTO BLEND TEMPERATURE FORECAST. THE 8-14 DAY PRECIPITATION PROG IS BASED ON THE NEURAL NET AND ANALOG SPECIFICATIONS FROM THE OFFICIAL BLEND... ANALOG SPECIFICATIONS FROM THE GFS ENSEMBLES... AND THE CPC AUTO BLEND PRECIPITATION FORECAST. 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 JUNE 19. 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: 19690602 - 19940510 - 19790522 - 19540519 - 19580521 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: 19690602 - 19790522 - 19940510 - 19750529 - 19990523 6 to 10 day Outlook Table OUTLOOK FOR MAY 26 - 30, 2008 STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN WASHINGTON A A OREGON N A NRN CALIF N A SRN CALIF B N IDAHO N A NEVADA N A W MONTANA N A E MONTANA N A WYOMING N A UTAH N N ARIZONA B N COLORADO N A NEW MEXICO N N N DAKOTA B A S DAKOTA N A NEBRASKA N A KANSAS A A OKLAHOMA A A N TEXAS A N S TEXAS A N W TEXAS A N MINNESOTA B A IOWA N A MISSOURI A A ARKANSAS A A LOUISIANA A N WISCONSIN N A ILLINOIS A A MISSISSIPPI A N MICHIGAN N N INDIANA N A OHIO N N KENTUCKY N A TENNESSEE A A ALABAMA A N NEW YORK N B VERMONT N B NEW HAMP N B MAINE B B MASS N B CONN N B RHODE IS N B PENN N N NEW JERSEY N B W VIRGINIA N N MARYLAND N N DELAWARE N N VIRGINIA N N N CAROLINA N N S CAROLINA N N GEORGIA N N FL PNHDL N N FL PENIN N N AK N SLOPE A N AK ALEUTIAN A N AK WESTERN A A AK INT BSN A N AK S INT A N AK SO COAST A N AK PNHDL A B 8 to 14 day Outlook Table OUTLOOK FOR MAY 28 - JUN 03, 2008 STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN WASHINGTON N A OREGON A A NRN CALIF A N SRN CALIF N B IDAHO N A NEVADA N N W MONTANA N A E MONTANA B A WYOMING N A UTAH N N ARIZONA B B COLORADO A N NEW MEXICO A B N DAKOTA N A S DAKOTA N A NEBRASKA A A KANSAS A A OKLAHOMA A N N TEXAS A N S TEXAS N N W TEXAS A N MINNESOTA N A IOWA N A MISSOURI A A ARKANSAS A N LOUISIANA A N WISCONSIN N A ILLINOIS A A MISSISSIPPI A N MICHIGAN N A INDIANA A A OHIO A A KENTUCKY A N TENNESSEE A N ALABAMA A B 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 A N NEW JERSEY A N W VIRGINIA A N MARYLAND A N DELAWARE A N VIRGINIA A N N CAROLINA A N S CAROLINA A N GEORGIA A B FL PNHDL A B FL PENIN N B AK N SLOPE N N AK ALEUTIAN A B AK WESTERN A B AK INT BSN A N AK S INT A B AK SO COAST A B AK PNHDL A 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. $$