FXUS06 KWBC 211932 PMDMRD PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD 300 PM EDT MON SEPTEMBER 21 2015 6-10 DAY OUTLOOK FOR SEP 27 - OCT 01, 2015 TODAY’S ENSEMBLE MEANS ARE IN GOOD AGREEMENT ON PREDICTING ANOMALOUS RIDGING IN THE GULF OF ALASKA AND OVER MOST OF THE STATE, AN UNSEASONABLY DEEP TROUGH NEAR THE WEST COAST OF THE U.S., AND ANOMALOUS RIDGING OVER MUCH OF THE EASTERN TWO THIRDS OF THE CONUS. MODELS HAVE ALSO SHOWN GOOD RUN-TO-RUN CONSISTENCY OVER THE PAST SEVERAL DAYS, SO CONFIDENCE IS RELATIVELY HIGH. TODAY’S MANUAL 500-HPA BLEND FAVORS THE 0Z ECMWF ENSEMBLE DUE TO ITS RELATIVELY HIGH SKILL DURING THE PAST 60 DAYS. ABOVE NORMAL TEMPERATURES ARE STRONGLY FAVORED OVER MOST OF THE CONUS DUE TO ANOMALOUS SOUTHERLY FLOW AND RIDGING IN THE EASTERN HALF OF THE CONUS, EXCEPT OVER THE WESTERN CONUS WHERE AN ANOMALOUS TROUGH IS ANTICIPATED, INCREASING THE CHANCES FOR BELOW NORMAL TEMPERATURES THERE. ANOMALOUS TROUGHING OVER MOST OF ALASKA FAVORS BELOW NORMAL TEMPERATURES FOR MOST OF THE STATE. ONSHORE FLOW AND A STORM SYSTEM PREDICTED TO AFFECT ALASKA DURING THE PERIOD LEAD TO ENHANCED CHANCES FOR ABOVE MEDIAN PRECIPITATION FOR THE STATE. PROLONGED ANOMALOUS TROUGHING PREDICTED IN THE WESTERN U.S. FAVORS ABOVE MEDIAN PRECIPITATION FOR THE PACIFIC NORTHWEST AND INTO THE NORTHERN PLAINS. LARGE POSITIVE HEIGHT ANOMALIES IN THE EASTERN U.S. FAVOR BELOW MEDIAN PRECIPITATION FROM TEXAS INTO THE UPPER MISSISSIPPI VALLEY, GREAT LAKES, AND NORTHEAST. SOME TROPICAL ACTIVITY IS ANTICIPATED IN THE GULF OF MEXICO DURING THE PERIOD, THOUGH THERE IS STILL A GOOD DEAL OF UNCERTAINTY. THIS FAVORS ABOVE MEDIAN PRECIPITATION ALONG THE GULF COAST AND FOR FLORIDA AND THE CAROLINAS. TODAY'S OFFICIAL 500-HPA BLEND CONSISTS OF 20% OF TODAY'S 6Z GFS ENSEMBLE MEAN CENTERED ON DAY 8, 60% OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 8, AND 20% 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 GOOD AGREEMENT AMONG THE MODEL SOLUTIONS AND SURFACE TOOLS. 8-14 DAY OUTLOOK FOR SEP 29 - OCT 05, 2015 THE WEEK-2 500-HPA PATTERN ANTICIPATED ACROSS NORTH AMERICA IS VERY SIMILAR TO THAT IN THE 6-10 DAY PERIOD. THE TEMPERATURE AND PRECIPITATION PROBABILITY FORECASTS DURING THE WEEK-2 PERIOD ARE ALSO VERY SIMILAR TO THAT IN THE 6-10 DAY PERIOD, EXCEPT THAT AS UNCERTAINTY NATURALLY INCREASES FROM THE 6-10 DAY PERIOD TO THE WEEK-2 PERIOD, PROBABILITIES DECREASE. NEAR MEDIAN PRECIPITATION WILL ALSO BECOME MORE FAVORED OVER THE MIDDLE AND UPPER MISSISSIPPI VALLEY BY THE WEEK-2 PERIOD. THE OFFICIAL 8-14 DAY HEIGHT PROG CONSISTS OF: 30% OF YESTERDAY'S 18Z GFS ENSEMBLE MEAN CENTERED ON DAY 10, 20% OF YESTERDAY'S OPERATIONAL 18Z GFS CENTERED ON DAY 10, AND 50% OF YESTERDAY'S 12Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 10 FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD IS: ABOUT AVERAGE, 3 OUT OF 5, DUE TO FAIR AGREEMENT AMONG THE MODEL SOLUTIONS AND SURFACE TOOLS. FORECASTER: MIKE CHARLES 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 15 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: 19590907 - 19580918 - 19530926 - 19620911 - 19590902 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: 19590907 - 19561001 - 19580904 - 19590902 - 19580918 6-10 DAY OUTLOOK TABLE OUTLOOK FOR SEP 27 - OCT 01, 2015 STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN WASHINGTON B A OREGON B A NRN CALIF B N SRN CALIF A N IDAHO B A NEVADA B N W MONTANA N A E MONTANA A A WYOMING A A UTAH A A ARIZONA A N COLORADO A A NEW MEXICO A N N DAKOTA A A S DAKOTA A A NEBRASKA A A KANSAS A B OKLAHOMA A B N TEXAS A B S TEXAS A B W TEXAS A B MINNESOTA A A IOWA A B MISSOURI A B ARKANSAS A B LOUISIANA A A WISCONSIN A B ILLINOIS A B MISSISSIPPI A A MICHIGAN A B INDIANA A B OHIO A B KENTUCKY A B TENNESSEE A B 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 B NEW JERSEY A B W VIRGINIA A B MARYLAND A B DELAWARE A B VIRGINIA A B N CAROLINA A A S CAROLINA A A GEORGIA A A FL PNHDL A A FL PENIN A A AK N SLOPE B A AK ALEUTIAN N A AK WESTERN B A AK INT BSN B A AK S INT B A AK SO COAST B A AK PNHDL N A 8-14 DAY OUTLOOK TABLE OUTLOOK FOR SEP 29 - OCT 05, 2015 STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN WASHINGTON B A OREGON B A NRN CALIF B N SRN CALIF A N IDAHO B N NEVADA B N W MONTANA N A E MONTANA A A WYOMING A N UTAH A N ARIZONA A N COLORADO A A NEW MEXICO A N N DAKOTA A A S DAKOTA A A NEBRASKA A A KANSAS A A OKLAHOMA A N N TEXAS A B S TEXAS A B W TEXAS A N MINNESOTA A A IOWA A A MISSOURI A N ARKANSAS A N LOUISIANA A A WISCONSIN A A ILLINOIS A N MISSISSIPPI A A MICHIGAN A B INDIANA A N OHIO A B KENTUCKY A N TENNESSEE A N 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 B NEW JERSEY A B W VIRGINIA A B MARYLAND A B DELAWARE A B VIRGINIA A N N CAROLINA A A S CAROLINA A A GEORGIA A A FL PNHDL A A FL PENIN A A AK N SLOPE B A AK ALEUTIAN A A AK WESTERN B A AK INT BSN B A AK S INT B A AK SO COAST B A AK PNHDL N 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. $$