187 FXUS06 KWBC 231902 PMDMRD PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD 300 PM EDT WED MAY 23 2018 6-10 DAY OUTLOOK FOR MAY 29 - JUN 02, 2018 THE 0Z GFS AND 0Z ECMWF ENSEMBLE MEANS AND THEIR DETERMINISTIC MODEL SOLUTIONS ARE IN GOOD AGREEMENT ON THE 500-HPA LONGWAVE FEATURES INCLUDING: A WEAKENING UPPER-LEVEL LOW OVER THE SOUTHEAST, A STRENGTHENING UPPER-LEVEL RIDGE OVER THE HIGHER LATITUDES OF THE CENTRAL AND EASTERN U.S., AND AN UPPER-LEVEL TROUGH OF VARYING AMPLITUDE ENTERING THE WESTERN U.S. THE 0Z ECMWF ENSEMBLE MEAN AND ITS DETERMINISTIC RUN HAVE THE MOST AMPLIFIED TROUGH ENTERING THE WESTERN U.S. DURING THIS 5-DAY PERIOD, WHICH IS PREFERRED SINCE THIS SOLUTION TELECONNECTS WELL WITH A POSITIVE 500-HPA HEIGHT ANOMALY CENTER SOUTH OF THE ALEUTIANS. ABOVE-NORMAL TEMPERATURES ARE FAVORED THROUGHOUT THE CONUS BUT FORECAST CONFIDENCE IS LOWER IN A COUPLE OF AREAS. WIDESPREAD RAINFALL EXPECTED AT LEAST EARLY IN THE PERIOD REDUCE PROBABILITIES FOR ABOVE-NORMAL TEMPERATURES ACROSS THE SOUTHEAST, WHILE AN UPPER-LEVEL TROUGH ENTERING THE WESTERN U.S. DECREASES PROBABILITIES FOR ABOVE-NORMAL TEMPERATURES ACROSS THIS REGION. THE HIGHEST PROBABILITIES FOR ABOVE-NORMAL TEMPERATURES ARE FORECAST ACROSS THE GREAT PLAINS WHERE THE DETERMINISTIC 0Z ECMWF MODEL INDICATES 500-HPA HEIGHTS INCREASING TO 594DM OVER THE SOUTH-CENTRAL CONUS BY JUNE 1. AN UPPER-LEVEL LOW EARLY IN THE PERIOD AND THE POTENTIAL REMNANTS OF THE FIRST TROPICAL CYCLONE OF THE SEASON INCREASE CHANCES FOR ABOVE-NORMAL PRECIPITATION FROM THE GULF COAST NORTH TO THE OHIO VALLEY AND MID-ATLANTIC. THE GFS AND ECMWF ENSEMBLE MEANS INDICATE LOCALLY MORE THAN 2 INCHES OF RAINFALL ACROSS THE SOUTHEAST DURING THIS 5-DAY PERIOD. A BUILDING RIDGE ALOFT ENHANCE ODDS FOR BELOW-NORMAL PRECIPITATION FROM TEXAS NORTHEAST TO THE GREAT LAKES AND NORTHEAST. DOWNSTREAM OF AN UPPER-LEVEL TROUGH, ABOVE-NORMAL PRECIPITATION IS FAVORED ACROSS PARTS OF THE GREAT BASIN, NORTHERN AND CENTRAL ROCKIES, AND THE NORTHERN AND CENTRAL GREAT PLAINS. INCREASED CHANCES OF BELOW-NORMAL PRECIPITATION ARE FORECAST FOR THE PACIFIC NORTHWEST, DUE TO UPSTREAM RIDGING OVER THE GULF OF ALASKA. AN UPPER-LEVEL TROUGH UPSTREAM OVER THE BERING SEA INCREASES CHANCES FOR ABOVE-NORMAL PRECIPITATION ACROSS SOUTHWEST ALASKA AND THE ALEUTIANS, WHILE MEAN RIDGING ALOFT TILTS THE ODDS TO BELOW-NORMAL PRECIPITATION ACROSS EASTERN MAINLAND ALASKA. TEMPERATURE TOOLS DERIVED FROM THE DYNAMICAL MODELS SUPPORT BELOW-NORMAL TEMPERATURES ACROSS SOUTHEAST MAINLAND ALASKA. NEAR TO ABOVE NORMAL TEMPERATURES ARE FAVORED FOR THE ALEUTIANS AND WESTERN COASTAL ALASKA, IN PART DUE TO ABOVE NORMAL SEA SURFACE TEMPERATURES. THE OFFICIAL 6-10 DAY 500-HPA HEIGHT BLEND CONSISTS OF 25% OF TODAY'S 0Z GFS ENSEMBLE MEAN CENTERED ON DAY 8, 50% OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 8, AND 25% OF TODAY'S OPERATIONAL 0Z ECMWF CENTERED ON DAY 8 FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: ABOVE AVERAGE, 4 OUT OF 5, DUE TO EXCELLENT AGREEMENT AMONG THE TEMPERATURE TOOLS AND GOOD AGREEMENT BETWEEN THE ANALOG PRECIPITATION TOOLS AND DYNAMICAL MODEL GUIDANCE. 8-14 DAY OUTLOOK FOR MAY 31 - JUN 06, 2018 EARLY IN WEEK-2, THE PREFERRED ECMWF MODEL INDICATES AN AMPLIFIED 500-HPA TROUGH ENTERING THE WESTERN U.S. DOWNSTREAM OF THIS UPPER-LEVEL TROUGH, 500-HPA HEIGHTS ARE FORECAST TO INCREASE AND ARE LIKELY TO EXCEED 588DM FROM THE SOUTHERN GREAT PLAINS NORTHEAST TO THE MIDDLE MISSISSIPPI VALLEY. THIS EVOLVING LONGWAVE PATTERN YIELDS THE HIGHEST ODDS FOR ABOVE NORMAL TEMPERATURES ACROSS THE CENTRAL AND SOUTHERN GREAT PLAINS WHERE AN INCREASING RISK OF AN EARLY SEASON HEAT WAVE EXISTS. FOLLOWING A WET EARLY SPRING, PRECIPITATION HAS AVERAGED BELOW NORMAL ACROSS THE EASTERN THIRD OF TEXAS WHERE TOPSOILS ARE DRYING OUT. SOIL MOISTURE CURRENTLY RANKS IN THE LOWEST 20TH PERCENTILE ACROSS PARTS OF THE CENTRAL AND SOUTHERN GREAT PLAINS. THE LOW SOIL MOISTURE ALSO SUPPORTS HIGHER PROBABILITIES FOR ABOVE-NORMAL TEMPERATURES ACROSS THE CENTRAL AND SOUTHERN GREAT PLAINS. ELSEWHERE, MUCH OF THE CAROLINAS, GEORGIA, AND FLORIDA HAVE EXPERIENCED A VERY WET MAY. ALTHOUGH THE LONGWAVE PATTERN SUPPORTS ABOVE-NORMAL TEMPERATURES ACROSS THE SOUTHEASTERN U.S., THE INCREASINGLY WET TOPSOIL LIMITS THE PROBABILITIES FOR ABOVE-NORMAL TEMPERATURES. NEAR NORMAL TEMPERATURES ARE FAVORED FOR PARTS OF CALIFORNIA BASED ON THE EXPECTATION OF AN AMPLIFIED TROUGH ENTERING THE WESTERN U.S. DURING WEEK-2 AND SUPPORT FROM THE ANALOG TEMPERATURE TOOLS. FORECAST CONFIDENCE IS MUCH LOWER IN THE PRECIPITATION OUTLOOK SINCE THE UPPER-LEVEL LOW OVER THE SOUTHEAST, RESPONSIBLE FOR A MULTI-DAY HEAVY RAINFALL EVENT PRECEDING THIS PERIOD, IS EXPECTED TO DISSIPATE EARLY IN WEEK-2. AN UPPER-LEVEL TROUGH, EARLY DURING WEEK-2, FAVORS ABOVE-NORMAL PRECIPITATION FROM THE GREAT BASIN NORTHEAST TO THE NORTHERN GREAT PLAINS. BELOW-NORMAL PRECIPITATION IS FAVORED FROM KANSAS SOUTH TO TEXAS DUE TO ANOMALOUS RIDGING ALOFT AND THE EXPECTATION THAT A STRONG CAPPING INVERSION WILL INHIBIT CONVECTION. THE UPPER-LEVEL TROUGH INITIALLY OVER THE BERING SEA TILTS THE ODDS TO ABOVE NORMAL PRECIPITATION ACROSS THE ALEUTIANS AND WESTERN ALASKA, WHILE AN UPPER-LEVEL RIDGE INCREASES CHANCES FOR BELOW NORMAL PRECIPITATION ACROSS EASTERN MAINLAND ALASKA. THE TEMPERATURE OUTLOOK IS BASED ON DYNAMICAL MODEL CONSENSUS AND SEA SURFACE ANOMALY CONSIDERATIONS. THE OFFICIAL 8-14 DAY 500-HPA HEIGHT BLEND CONSISTS OF: 25% OF TODAY'S 0Z GFS ENSEMBLE MEAN CENTERED ON DAY 11, AND 75% OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 11 FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD: AVERAGE, 3 OUT OF 5, DUE TO GOOD AGREEMENT IN THE TEMPERATURE OUTLOOK OFFSET BY INCREASED UNCERTAINTY IN THE PRECIPITATION OUTLOOK. FORECASTER: BRAD PUGH NOTES: AUTOMATED FORECASTS ARE ISSUED ON SATURDAY AND SUNDAY. OCCASIONALLY MANUAL INTERVENTION IS NECESSARY TO ADDRESS QUALITY CONTROL AND CONSISTENCY ISSUES. IN THESE CASES, FORECASTS ARE MANUALLY DRAWN BUT A FULL DISCUSSION IS NOT ISSUED. 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 THE TEMPERATURE MAP SHOWS REGIONS WITH > 33% CHANCE OF BEING WARMER (ORANGE, "A"), COLDER (BLUE, "B"), OR CLOSE TO (UNSHADED, "N"). HISTORICAL AVERAGE VALUES FOR THE CALENDAR PERIOD OF THE FORECAST (DASHES, "F"). LABELS ON THE SHADED LINES GIVE THE PROBABILITY (> 33%) OF THE MORE LIKELY CATEGORY (B OR A). PROBABILITY OF N IS ALWAYS < 40%. THE PRECIPITATION MAP SHOWS REGIONS WITH > 33% CHANCE OF BEING WETTER (GREEN, "A"), DRIER (TAN, "B"), OR CLOSE TO (UNSHADED, "N"). HISTORICAL MEDIAN VALUES FOR THE CALENDAR PERIOD OF THE FORECAST (DASHES, "INCHES"). LABELS ON THE SHADED LINES GIVE THE PROBABILITY (> 33%) OF THE MORE LIKELY CATEGORY (B OR A). PROBABILITY OF N IS ALWAYS < 40%. 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 CLIMATE PREDICTION CENTER USES 1981-2010 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 21. 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: 19910513 - 19950602 - 19610603 - 19700522 - 19940523 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 7 DAY PERIODS CENTERED ON THE FOLLOWING DATES: 19910513 - 19610604 - 20070512 - 19950601 - 19870504 6-10 DAY OUTLOOK TABLE OUTLOOK FOR MAY 29 - JUN 02, 2018 STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN WASHINGTON A B OREGON A B NRN CALIF A N SRN CALIF A N IDAHO A A NEVADA A A W MONTANA A A E MONTANA A A WYOMING A A UTAH A A ARIZONA A N COLORADO A A NEW MEXICO A B N DAKOTA A A S DAKOTA A A NEBRASKA A A KANSAS A N OKLAHOMA A B N TEXAS A B S TEXAS A B W TEXAS A B MINNESOTA A A IOWA A N MISSOURI A B ARKANSAS A N LOUISIANA A A WISCONSIN A B ILLINOIS A B MISSISSIPPI A A MICHIGAN A B INDIANA A A OHIO A A KENTUCKY A A TENNESSEE A A ALABAMA A A NEW YORK A B VERMONT A B NEW HAMP A B MAINE A B MASS A B CONN A B RHODE IS A B PENN A A NEW JERSEY A B W VIRGINIA A A MARYLAND A A DELAWARE A A VIRGINIA A A N CAROLINA A A S CAROLINA A A GEORGIA A A FL PNHDL A A FL PENIN A A AK N SLOPE A N AK ALEUTIAN A A AK WESTERN B A AK INT BSN B B AK S INT B A AK SO COAST B N AK PNHDL B N 8-14 DAY OUTLOOK TABLE OUTLOOK FOR MAY 31 - JUN 06, 2018 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 A NEVADA A A W MONTANA A N E MONTANA A A WYOMING A A UTAH A N ARIZONA A N COLORADO A N NEW MEXICO A B N DAKOTA A N S DAKOTA A N NEBRASKA A N KANSAS A B OKLAHOMA A B N TEXAS A B S TEXAS A B W TEXAS A B MINNESOTA A N IOWA A N MISSOURI A N ARKANSAS A N LOUISIANA A A WISCONSIN A N ILLINOIS A N MISSISSIPPI A A MICHIGAN A N INDIANA A A OHIO A A KENTUCKY A A TENNESSEE A A ALABAMA A A NEW YORK A B VERMONT A B NEW HAMP A B MAINE A B MASS A B CONN A B RHODE IS A B PENN A N NEW JERSEY A N W VIRGINIA A A MARYLAND A A DELAWARE A N VIRGINIA A A N CAROLINA A A S CAROLINA A A GEORGIA A A FL PNHDL A A FL PENIN A A AK N SLOPE A N AK ALEUTIAN A A AK WESTERN A A AK INT BSN A B AK S INT B B AK SO COAST B N 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. $$