829 FXUS06 KWBC 201902 PMDMRD PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD 300 PM EDT THU SEPTEMBER 20 2018 6-10 DAY OUTLOOK FOR SEP 26 - 30 2018 TODAY'S MODELS ARE IN VERY GOOD AGREEMENT ON THE OVERALL 500-HPA GEOPOTENTIAL HEIGHT PATTERN FORECAST DURING THE 6-10 DAY PERIOD. A DEEP TROUGH IS FORECAST OVER THE ALEUTIANS, WHILE A STRONG, VERY ANOMALOUS RIDGE IS FORECAST OVER MAINLAND ALASKA AND ALONG THE WEST COAST OF THE CONUS. DOWNSTREAM A DEEP LONG-WAVE TROUGH IS CENTERED OVER PARTS OF THE UPPER MIDWEST AND WESTERN GREAT LAKES REGION, AND SOME RIDGING IS FORECAST TO PERSIST IN PARTS OF THE SOUTHEAST. LARGE POSITIVE HEIGHT ANOMALIES OVER ALASKA STRONGLY FAVOR ABOVE NORMAL TEMPERATURES FOR THE ENTIRE STATE. THESE POSITIVE HEIGHT ANOMALIES EXTEND SOUTH OVER MUCH OF THE WESTERN CONUS, FAVORING ABOVE NORMAL TEMPERATURES FOR PARTS OF THE WESTERN CONUS. COLD AIR ADVECTION BENEATH A PREDICTED ANOMALOUSLY DEEP TROUGH STRONGLY FAVORS BELOW NORMAL TEMPERATURES OVER THE CENTRAL U.S., MOST LIKELY IN THE NORTHERN PLAINS WHERE MODELS AND TOOLS HAVE THE BEST AGREEMENT, AND WHERE BELOW-NORMAL TEMPERATURES ARE FORECAST TO BE THE MOST PERSISTENT. AHEAD OF THE TROUGH, ABOVE NORMAL TEMPERATURES ARE FAVORED FOR MUCH OF THE EASTERN CONUS. THE STRONG RIDGE PREDICTED OVER THE WESTERN U.S. INCREASES THE LIKELIHOOD OF NEAR TO BELOW NORMAL PRECIPITATION FOR THE WESTERN CONUS AND THE ALASKA PANHANDLE. SEVERAL STORM SYSTEMS ARE FORECAST TO TRACK INTO ALASKA AND OVER THIS RIDGE, ENHANCING THE LIKELIHOOD OF ABOVE NORMAL PRECIPITATION FOR MOST OF ALASKA. A COUPLE OF FRONTAL PASSAGES IN THE EASTERN CONUS INCREASE THE CHANCES OF ABOVE NORMAL PRECIPITATION THERE FOR THE EASTERN HALF OF THE U.S., ESPECIALLY OVER PARTS OF TEXAS AND LOUISIANA WHERE PRECIPITATION IS EXPECTED TO PERSIST ALONG A STALLED FRONTAL BOUNDARY. THE OFFICIAL 6-10 DAY 500-HPA HEIGHT BLEND CONSISTS OF 30% OF TODAY'S 6Z GFS ENSEMBLE MEAN CENTERED ON DAY 8, 40% OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 8, AND 30% OF TODAY'S OPERATIONAL 0Z ECMWF CENTERED ON DAY 8 FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: WELL ABOVE AVERAGE, 5 OUT OF 5, DUE TO VERY GOOD AGREEMENT AMONG THE MODELS AND TOOLS AND A WELL-DEFINED HIGHLY AMPLIFIED PATTERN. 8-14 DAY OUTLOOK FOR SEP 28 - OCT 04, 2018 DURING THE WEEK-2 PERIOD MODELS ARE PREDICTING A VERY SIMILAR PATTERN TO THE 6-10 DAY PERIOD, WITH THE TROUGH OVER THE CONUS SHIFTED SLIGHTLY EASTWARD. THE TEMPERATURE PROBABILITY FORECAST FOR WEEK-2 IS SIMILAR TO THE 6-10 DAY PERIOD, EXCEPT THE PROBABILITIES OF BELOW NORMAL TEMPERATURES ARE SHIFTED EASTWARD, LEAVING ONLY COASTAL AREAS OF THE EASTERN CONUS WITH FAVORED ABOVE NORMAL TEMPERATURES IN WEEK-2. THE PRECIPITATION PROBABILITY FORECAST FOR WEEK-2 IS ALSO SIMILAR TO THE 6-10 DAY PERIOD, EXCEPT BELOW NORMAL PRECIPITATION IS FAVORED IN PARTS OF THE NORTHERN PLAINS IN WEEK-2 AS THE HEIGHTS ARE EXPECTED TO RISE AND THE TROUGH SHIFTS EASTWARD. THE OFFICIAL 8-14 DAY 500-HPA HEIGHT BLEND CONSISTS OF: 40% OF TODAY'S 6Z GFS ENSEMBLE MEAN CENTERED ON DAY 11, AND 60% OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 11 FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD: ABOVE AVERAGE, 4 OUT OF 5, DUE TO VERY GOOD AGREEMENT AMONG THE MODELS AND TEMPERATURE TOOLS AND A WELL-DEFINED HIGHLY AMPLIFIED PATTERN, OFFSET SLIGHTLY BY SOME DIFFERENCES BETWEEN THE PRECIPITATION TOOLS. FORECASTER: MIKE C 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 OCTOBER 18. 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: 19720918 - 19960929 - 20001001 - 19591004 - 19731004 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: 19720917 - 19800920 - 20001001 - 19740927 - 19731002 6-10 DAY OUTLOOK TABLE OUTLOOK FOR SEP 26 - 30 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 B B NEVADA A N W MONTANA B B E MONTANA B N WYOMING B B UTAH A B ARIZONA A B COLORADO B B NEW MEXICO A B N DAKOTA B A S DAKOTA B N NEBRASKA B N KANSAS B N OKLAHOMA B A N TEXAS B A S TEXAS B A W TEXAS B A MINNESOTA B A IOWA B A MISSOURI B A ARKANSAS N A LOUISIANA A A WISCONSIN B A ILLINOIS B A MISSISSIPPI A A MICHIGAN N A INDIANA N A OHIO A A KENTUCKY A A TENNESSEE A A ALABAMA A A NEW YORK A A VERMONT A A NEW HAMP A A MAINE A A MASS A A CONN A A RHODE IS A A PENN A A NEW JERSEY A A 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 A AK ALEUTIAN A A AK WESTERN A A AK INT BSN A A AK S INT A A AK SO COAST A A AK PNHDL A B 8-14 DAY OUTLOOK TABLE OUTLOOK FOR SEP 28 - OCT 04, 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 B NEVADA A N W MONTANA B B E MONTANA B B WYOMING B B UTAH A N ARIZONA A N COLORADO A B NEW MEXICO A N N DAKOTA B B S DAKOTA B B NEBRASKA B N KANSAS B N OKLAHOMA B A N TEXAS B A S TEXAS B A W TEXAS B A MINNESOTA B N IOWA B A MISSOURI B A ARKANSAS B A LOUISIANA N A WISCONSIN B A ILLINOIS B A MISSISSIPPI B A MICHIGAN B A INDIANA B A OHIO B A KENTUCKY B A TENNESSEE B A ALABAMA N A NEW YORK N A VERMONT N A NEW HAMP N A MAINE N A MASS A A CONN A A RHODE IS A A PENN B A NEW JERSEY N A W VIRGINIA B A MARYLAND N A DELAWARE N A VIRGINIA N A N CAROLINA N A S CAROLINA A A GEORGIA A A FL PNHDL A A FL PENIN A A AK N SLOPE A A AK ALEUTIAN A A AK WESTERN A A AK INT BSN A A AK S INT A A AK SO COAST A A 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. $$