967  
FXUS06 KWBC 082047  
PMDMRD  
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS  
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD  
300 PM EST WED NOVEMBER 08 2017  
 
6-10 DAY OUTLOOK FOR NOV 14 - 18 2017  
 
TODAY'S DYNAMICAL MODEL SOLUTIONS ARE IN GOOD AGREEMENT ON THEIR 500-HPA  
CIRCULATION FORECASTS FOR THE 6-10 DAY PERIOD OVER THE NORTH AMERICAN REGION. A  
STRONG RIDGE IS FORECAST OVER THE BERING SEA AND WESTERN ALASKA, WHILE A TROUGH  
IS PREDICTED OVER EASTERN ALASKA, EXTENDING INTO THE NORTH PACIFIC. ABOVE  
NORMAL 500-HPA HEIGHTS ARE PREDICTED IN AN AREA STRETCHING FROM THE SOUTHWEST  
ACROSS THE CENTRAL AND SOUTHERN PLAINS TO THE MISSISSIPPI VALLEY AND GREAT  
LAKES REGION. A TROUGH AND NEAR TO BELOW NORMAL 500-HPA HEIGHTS ARE FORECAST  
OVER THE ATLANTIC COAST. MODEL ENSEMBLE SPREAD IS GREATER THAN YESTERDAY,  
INDICATING INCREASING UNCERTAINTY ON THE CIRCULATION PATTERN.  
 
ABOVE NORMAL TEMPERATURES ARE MOST LIKELY FOR THE WESTERN ALEUTIANS AND PARTS  
OF THE NORTHWEST COAST OF ALASKA UNDER LARGE POSITIVE 500-HPA HEIGHT ANOMALIES  
ASSOCIATED WITH A PREDICTED RIDGE. ABOVE NORMAL TEMPERATURES ARE MOST LIKELY  
FOR THE NORTH SLOPE, WITH ABOVE NORMAL SEA SURFACE TEMPERATURES AND PREDICTED  
STRONG NORTHERLY FLOW. BELOW NORMAL TEMPERATURES ARE LIKELY FOR MOST OTHER  
AREAS OF ALASKA, ESPECIALLY THE SOUTHEASTERN COAST OF THE STATE, UNDER STRONGLY  
NEGATIVE 500-HPA HEIGHT ANOMALIES. PROBABILITIES OF BELOW NORMAL TEMPERATURES  
ARE ALSO ENHANCED FOR PARTS OF THE PACIFIC NORTHWEST, UNDER BELOW NORMAL  
500-HPA HEIGHTS ASSOCIATED WITH A PREDICTED TROUGH. ABOVE NORMAL TEMPERATURES  
ARE MOST LIKELY FOR SOUTHWESTERN AREAS OF THE CONUS EXTENDING ACROSS THE GREAT  
PLAINS STATES TO THE MISSISSIPPI VALLEY AND WESTERN GREAT LAKES REGION UNDER  
PREDICTED ABOVE NORMAL 500-HPA HEIGHTS. NEAR NORMAL TEMPERATURES ARE MORE  
LIKELY FOR PARTS OF THE EASTERN CONUS WITH NEAR TO BELOW NORMAL 500-HPA HEIGHTS  
UNDER A PREDICTED TROUGH.  
 
ABOVE NORMAL PRECIPITATION IS LIKELY FOR THE NORTH SLOPE OF ALASKA WITH  
PREDICTED NORTHERLY MID-LEVEL FLOW, WHILE BELOW NORMAL PRECIPITATION IS MOST  
LIKELY FOR INTERIOR AND SOUTHERN REGIONS OF ALASKA, AHEAD OF A PREDICTED RIDGE.  
ABOVE NORMAL PRECIPITATION IS MOST LIKELY FOR NORTHERN CALIFORNIA, NORTHERN  
NEVADA, THE PACIFIC NORTHWEST, AND THE NORTHERN ROCKIES, AHEAD OF A PREDICTED  
TROUGH OVER THE NORTH PACIFIC. THE PROBABILITIES OF ABOVE NORMAL PRECIPITATION  
ARE SLIGHTLY ELEVATED FOR THE 6-10 DAY PERIOD OVER THE WESTERN GREAT LAKES  
REGION SOUTHWARD INTO THE CENTRAL MISSISSIPPI VALLEY.  
 
THE OFFICIAL 6-10 DAY 500-HPA HEIGHT BLEND CONSISTS OF 10% OF TODAY'S 0Z GFS  
ENSEMBLE MEAN CENTERED ON DAY 8, 25% OF TODAY'S 6Z GFS ENSEMBLE MEAN CENTERED  
ON DAY 8, 40% OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 8, AND 25%  
OF TODAY'S 0Z CANADIAN ENSEMBLE MEAN CENTERED ON DAY 8  
 
 
FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: ABOVE AVERAGE, 3 OUT OF 5, DUE TO  
GOOD MODEL AGREEMENT ON THE EXPECTED CIRCULATION PATTERN, MODERATE ENSEMBLE  
SPREAD, AND FAIR AGREEMENT AMONG THE TEMPERATURE AND PRECIPITATION TOOLS.  
 
8-14 DAY OUTLOOK FOR NOV 16 - 22 2017  
 
THE OVERALL 500-HPA CIRCULATION PATTERN PREDICTED FOR THE WEEK 2 PERIOD  
INDICATES SMALL CHANGES FROM THE 6-10 DAY PERIOD FORECAST, HOWEVER, ENSEMBLE  
SPREAD INCREASES SUBSTANTIALLY, INDICATING GREATER FORECAST UNCERTAINTY. SOME  
RETROGRESSION OF A PREDICTED TROUGH OVER EASTERN ALASKA AND NEAR THE COAST OF  
THE PACIFIC NORTHWEST IS INDICATED BETWEEN 6-10 DAY AND WEEK 2 PERIODS BY MODEL  
SOLUTIONS. MEAN 500-HPA HEIGHT ANOMALIES ARE SOMEWHAT WEAKER OVER THE CONUS IN  
THE WEEK 2 FORECASTS, DUE TO INCREASING ENSEMBLE SPREAD, AND THE AREA OF  
NEGATIVE 500-HPA HEIGHT ANOMALIES OVER THE PACIFIC NORTHWEST IS MUCH LESS IN  
WEEK 2 COMPARED TO THE 6-10 DAY PERIOD FORECAST, ASSOCIATED WITH PREDICTED  
RETROGRESSION OF THE MEAN TROUGH AXIS.  
 
BELOW NORMAL TEMPERATURES ARE MOST LIKELY FOR A LARGE AREA OF SOUTHEASTERN  
ALASKA WITH PREDICTED BELOW NORMAL 500-HPA HEIGHTS. ABOVE NORMAL TEMPERATURES  
REMAIN MOST LIKELY FOR PARTS OF THE WESTERN ALEUTIANS, AS WELL AS THE NORTHWEST  
COAST AND THE NORTH SLOPE OF ALASKA. THE LIKELIHOOD OF BELOW NORMAL  
TEMPERATURES HAS DECREASED FOR MOST OF THE PACIFIC NORTHWEST, WHILE THE  
PROBABILITIES OF NEAR AND ABOVE NORMAL HAVE INCREASED ALONG WITH INCREASING  
AVERAGE 500-HPA HEIGHTS IN WEEK 2. ABOVE NORMAL TEMPERATURES ARE LIKELY FROM  
CALIFORNIA AND SOUTHERN OREGON IN THE WEST, ACROSS THE CENTRAL AND SOUTHERN  
PLAINS STATES TO WESTERN PORTIONS OF THE OHIO VALLEY AND SOUTHEAST REGIONS,  
UNDER PREDICTED ABOVE NORMAL 500-HPA HEIGHTS AND MEAN ZONAL FLOW. ABOVE NORMAL  
TEMPERATURES ARE MOST LIKELY FOR THE NORTHEAST. BELOW NORMAL TEMPERATURES ARE  
MOST LIKELY FOR THE ATLANTIC COAST OF THE SOUTHEAST IN THE WEEK 2 PERIOD, UNDER  
ANOMALOUSLY NORTHERLY FLOW. NEAR TO BELOW NORMAL TEMPERATURES ARE INDICATED FOR  
PARTS OF THE NORTHERN PLAINS AND WESTERN GREAT LAKES REGION, UNDER PREDICTED  
NEAR TO BELOW NORMAL 500-HPA HEIGHTS.  
 
ABOVE NORMAL PRECIPITATION IS MOST LIKELY FOR THE NORTHWEST CONUS INTO PARTS OF  
EASTERN MONTANA, AHEAD OF A PREDICTED TROUGH, AND FROM THE GREAT LAKES REGION  
INTO THE CENTRAL MISSISSIPPI AND OHIO VALLEYS, AS WELL AS NORTHERN AREAS OF THE  
NORTHEAST, WITH PREDOMINANT TROUGHING IN MODEL ENSEMBLE MEMBERS. BELOW NORMAL  
PRECIPITATION IS INDICATED FOR MOST OF THE REMAINING AREAS OF THE CONUS, EXCEPT  
FOR CLIMATOLOGICALLY DRY AREAS OF THE SOUTHWEST WHERE NEAR NORMAL PRECIPITATION  
IS INDICATED. AREAS OF SOUTHERN ALASKA ARE PREDICTED TO HAVE BELOW NORMAL  
PRECIPITATION IN THE WEEK 2 PERIOD, WHILE ABOVE NORMAL PRECIPITATION IS LIKELY  
FOR PARTS OF THE NORTH SLOPE, UNDER PREDICTED NORTHERLY FLOW.  
 
THE OFFICIAL 8-14 DAY 500-HPA HEIGHT BLEND CONSISTS OF: 30% OF TODAY'S 6Z GFS  
ENSEMBLE MEAN CENTERED ON DAY 11, 50% OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN  
CENTERED ON DAY 11, AND 20% OF TODAY'S 0Z CANADIAN ENSEMBLE MEAN CENTERED ON  
DAY 11  
 
FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD IS: ABOUT AVERAGE, 3 OUT OF 5, DUE  
TO GOOD AGREEMENT AMONG THE ENSEMBLE MEAN SOLUTIONS ON THE 500-HPA CIRCULATION  
PATTERN DURING WEEK 2, OFFSET BY LARGE SPREAD AMONG THE ENSEMBLE MEMBERS.  
 
FORECASTER: D COLLINS  
 
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  
NOVEMBER 16  
 
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:  
19911022 - 20031106 - 19661112 - 19821019 - 19861115  
 
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:  
19661112 - 19811025 - 20031105 - 19821018 - 19711103  
 
6-10 DAY OUTLOOK TABLE  
OUTLOOK FOR NOV 14 - 18 2017  
 
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN  
WASHINGTON B A OREGON B A NRN CALIF B A  
SRN CALIF A B IDAHO N A NEVADA N A  
W MONTANA N A E MONTANA N A WYOMING A B  
UTAH A B ARIZONA A N COLORADO A B  
NEW MEXICO A B N DAKOTA A B S DAKOTA A B  
NEBRASKA A B 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 B WISCONSIN A A  
ILLINOIS A A MISSISSIPPI A B MICHIGAN A A  
INDIANA A A OHIO N N KENTUCKY N 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 N N NEW JERSEY N N W VIRGINIA N N  
MARYLAND N N DELAWARE N N VIRGINIA N B  
N CAROLINA N B S CAROLINA N B GEORGIA N B  
FL PNHDL N B FL PENIN N B AK N SLOPE N A  
AK ALEUTIAN B B AK WESTERN B B AK INT BSN B B  
AK S INT B B AK SO COAST B B AK PNHDL B B  
 
 
 
8-14 DAY OUTLOOK TABLE  
OUTLOOK FOR NOV 16 - 22 2017  
 
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN  
WASHINGTON N A OREGON N A NRN CALIF A A  
SRN CALIF A N IDAHO A A NEVADA A B  
W MONTANA N A E MONTANA N N WYOMING A B  
UTAH A B ARIZONA A N COLORADO A B  
NEW MEXICO A B N DAKOTA N B S DAKOTA A B  
NEBRASKA A B KANSAS A B OKLAHOMA A B  
N TEXAS A B S TEXAS A B W TEXAS A B  
MINNESOTA N B IOWA A B MISSOURI A B  
ARKANSAS A B LOUISIANA A B WISCONSIN N N  
ILLINOIS A N MISSISSIPPI A B MICHIGAN N N  
INDIANA A A OHIO N A KENTUCKY A A  
TENNESSEE A N ALABAMA A B NEW YORK N A  
VERMONT A A NEW HAMP A A MAINE A A  
MASS A N CONN A N RHODE IS A N  
PENN N N NEW JERSEY N N W VIRGINIA N N  
MARYLAND N N DELAWARE N N VIRGINIA N B  
N CAROLINA N B S CAROLINA B B GEORGIA N B  
FL PNHDL B B FL PENIN B B AK N SLOPE A A  
AK ALEUTIAN B B AK WESTERN B B AK INT BSN B B  
AK S INT B B AK SO COAST B B AK PNHDL B 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.  
 

 
 
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