672  
FXUS06 KWBC 162049  
PMDMRD  
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS  
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD  
300 PM EST THU NOVEMBER 16 2017  
 
6-10 DAY OUTLOOK FOR NOV 22 - 26 2017  
 
TODAY'S DYNAMICAL MODEL SOLUTIONS ARE IN FAIR 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 ALEUTIANS, WHILE A TROUGH IS PREDICTED OVER  
MUCH OF MAINLAND ALASKA, EXTENDING INTO THE NORTH PACIFIC. ANOTHER TROUGH IS  
FORECAST OVER THE EASTERN CONUS WITH A BLOCKING RIDGE OVER THE DAVIS STRAIT.  
ABOVE NORMAL 500-HPA HEIGHTS ARE PREDICTED OVER EXTREME SOUTHWESTERN MAINLAND  
ALASKA AND ACROSS THE WESTERN TWO-THIRDS OF THE CONUS. BELOW NORMAL 500-HPA  
HEIGHTS ARE FORECAST OVER THE REMAINDER OF THE CONUS AND MUCH OF ALASKA.  
 
BELOW NORMAL TEMPERATURES ARE LIKELY FOR MUCH OF ALASKA, UNDER NEGATIVE 500-HPA  
HEIGHT ANOMALIES AND OFFSHORE FLOW. ABOVE NORMAL TEMPERATURES ARE FAVORED FOR  
PARTS OF WESTERN MAINLAND ALASKA AND THE WESTERN ALEUTIANS, DUE TO ABOVE NORMAL  
SEA SURFACE TEMPERATURES IN SURROUNDING AREAS. ABOVE NORMAL TEMPERATURES ARE  
MOST LIKELY FOR THE WESTERN HALF OF THE CONUS UNDER PREDICTED ABOVE NORMAL  
500-HPA HEIGHTS. BELOW NORMAL TEMPERATURES ARE FAVORED FOR THE EASTERN CONUS  
FROM THE OHIO VALLEY NORTHWARD TO PARTS OF THE EASTERN GREAT LAKES AND THE  
NORTHEAST, DUE TO ANOMALOUS NORTHERLY FLOW. ABOVE NORMAL TEMPERATURES ARE  
LIKELY FOR SOUTHERN FLORIDA, DUE TO FORECAST ANOMALOUS SOUTHEASTERLY FLOW.  
 
ABOVE NORMAL PRECIPITATION IS FAVORED FOR NORTHERN AND WESTERN PARTS OF  
MAINLAND ALASKA AND THE SOUTHERN ALASKA PANHANDLE, DUE TO THE FORECAST TROUGH  
THERE AND ONSHORE FLOW. BELOW NORMAL PRECIPITATION IS MOST LIKELY FOR  
SOUTHEASTERN REGIONS OF MAINLAND ALASKA, AHEAD OF A PREDICTED RIDGE AND  
OFFSHORE FLOW. ABOVE NORMAL PRECIPITATION IS MOST LIKELY FOR CENTRAL AND  
NORTHERN CALIFORNIA, NORTHWESTERN NEVADA, THE PACIFIC NORTHWEST EASTWARD TO THE  
NORTHERN PLAINS, PARTS OF THE NORTHERN UPPER MISSISSIPPI VALLEY AND THE WESTERN  
GREAT LAKES, EAST OF A PREDICTED TROUGH OVER THE NORTH PACIFIC. ABOVE NORMAL  
PRECIPITATION IS FAVORED FOR FLORIDA PENINSULA, DUE TO FRONTAL ACTIVITY. BELOW  
NORMAL PRECIPITATION IS FORECAST FOR MOST OF THE REMAINING AREAS OF THE CONUS.  
 
THE OFFICIAL 6-10 DAY 500-HPA HEIGHT BLEND CONSISTS OF 10% OF TODAY'S 0Z GFS  
ENSEMBLE MEAN CENTERED ON DAY 8, 15% OF TODAY'S 6Z GFS ENSEMBLE MEAN CENTERED  
ON DAY 8, 15% OF TODAY'S GFS SUPERENSEMBLE MEAN CENTERED ON DAY 8, 5% OF  
TODAY'S OPERATIONAL 6Z GFS CENTERED ON DAY 8, 40% OF TODAY'S 0Z EUROPEAN  
ENSEMBLE MEAN CENTERED ON DAY 8, 5% OF TODAY'S OPERATIONAL 0Z ECMWF CENTERED ON  
DAY 8, AND 10% OF TODAY'S 0Z CANADIAN ENSEMBLE MEAN CENTERED ON DAY 8  
 
 
FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: ABOUT AVERAGE, 3 OUT OF 5, DUE TO  
FAIR MODEL AGREEMENT ON THE EXPECTED CIRCULATION PATTERN, OFFSET BY POOR  
AGREEMENT AMONG THE TEMPERATURE AND PRECIPITATION TOOLS OVER THE SOUTHEAST U.S.  
 
8-14 DAY OUTLOOK FOR NOV 24 - 30 2017  
 
THE OVERALL 500-HPA CIRCULATION PATTERN PREDICTED FOR THE WEEK 2 PERIOD IS  
SIMILAR TO THE 6-10 DAY PERIOD, ALTHOUGH AN UPPER-LEVEL PATTERN IS FORECAST TO  
DEAMPLIFY OVER THE FORECAST REGION. THE ENSEMBLE SPAGHETTI DIAGRAMS INDICATE  
MODERATE TO LARGE SPREAD ACROSS THE MAJORITY OF THE FORECAST DOMAIN. THE  
GREATEST WEIGHT FOR THE BLENDED 500-HPA HEIGHT FIELD WAS GIVEN TO THE ECMWF  
ENSEMBLE MEAN BASED ON CONSIDERATIONS OF RECENT SKILL AND ANALOG CORRELATIONS.  
 
BELOW NORMAL TEMPERATURES ARE MOST LIKELY FOR CENTRAL AND SOUTHERN MAINLAND  
ALASKA WITH PREDICTED BELOW NORMAL 500-HPA HEIGHTS AND PERSISTENT OFFSHORE  
FLOW. ABOVE NORMAL TEMPERATURES ARE FAVORED FOR PARTS OF THE WESTERN ALEUTIANS  
AND PARTS OF NORTHERN MAINLAND ALASKA, DUE TO ABOVE NORMAL SEA SURFACE  
TEMPERATURES IN SURROUNDING AREAS. ABOVE NORMAL TEMPERATURES ARE LIKELY FOR  
MOST OF THE WESTERN AND CENTRAL CONUS, UNDER PREDICTED ABOVE NORMAL 500-HPA  
HEIGHTS. BELOW NORMAL TEMPERATURES ARE FAVORED FOR MUCH OF THE MID-ATLANTIC  
COASTAL REGIONS, THE SOUTHEAST U.S. AND THE FLORIDA PENINSULA, ASSOCIATED WITH  
THE PREDICTED NORTHERLY FLOW.  
 
ABOVE NORMAL PRECIPITATION IS MOST LIKELY FROM CENTRAL AND NORTH CALIFORNIA,  
PARTS OF THE PACIFIC NORTHWEST EASTWARD TO NORTHERN PARTS OF THE NORTHERN  
PLAINS AND THE NORTHERN UPPER MISSISSIPPI VALLEY, AHEAD OF A PREDICTED TROUGH.  
BELOW NORMAL PRECIPITATION IS INDICATED FOR MOST OF THE REMAINING AREAS OF THE  
CONUS. AREAS OF EASTERN MAINLAND ALASKA ARE PREDICTED TO HAVE BELOW NORMAL  
PRECIPITATION, WHILE ABOVE NORMAL PRECIPITATION IS LIKELY FOR WESTERN MAINLAND  
ALASKA AND THE ALEUTIANS, UNDER PREDICTED ONSHORE FLOW AND CYCLONIC FLOW.  
 
THE OFFICIAL 8-14 DAY 500-HPA HEIGHT BLEND CONSISTS OF: 10% OF TODAY'S 0Z GFS  
ENSEMBLE MEAN CENTERED ON DAY 11, 15% OF TODAY'S 6Z GFS ENSEMBLE MEAN CENTERED  
ON DAY 11, 15% OF TODAY'S GFS SUPERENSEMBLE MEAN CENTERED ON DAY 11, 5% OF  
TODAY'S OPERATIONAL 0Z GFS CENTERED ON DAY 11, 45% OF TODAY'S 0Z EUROPEAN  
ENSEMBLE MEAN CENTERED ON DAY 11, AND 10% 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 MODERATE TO LARGE SPREAD AMONG THE ENSEMBLE  
MEMBERS  
 
FORECASTER: Y. FAN  
 
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  
DECEMBER 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:  
19661114 - 19701129 - 19731110 - 19661119 - 19731128  
 
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:  
19661113 - 19701127 - 19661118 - 19731110 - 20061122  
 
6-10 DAY OUTLOOK TABLE  
OUTLOOK FOR NOV 22 - 26 2017  
 
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN  
WASHINGTON A A OREGON A A NRN CALIF A A  
SRN CALIF A B IDAHO A A NEVADA A A  
W MONTANA A A E MONTANA A A WYOMING A A  
UTAH A B ARIZONA A B COLORADO A B  
NEW MEXICO A B N DAKOTA A A S DAKOTA A N  
NEBRASKA A B KANSAS A B OKLAHOMA A B  
N TEXAS A B S TEXAS N B W TEXAS A N  
MINNESOTA A A IOWA A B MISSOURI A B  
ARKANSAS N B LOUISIANA N B WISCONSIN N B  
ILLINOIS N B MISSISSIPPI N B MICHIGAN N N  
INDIANA B B OHIO B B KENTUCKY B B  
TENNESSEE N B ALABAMA N B NEW YORK B N  
VERMONT N B NEW HAMP N B MAINE N B  
MASS N B CONN B B RHODE IS B B  
PENN B B NEW JERSEY B B W VIRGINIA B B  
MARYLAND B B DELAWARE B B VIRGINIA B B  
N CAROLINA B B S CAROLINA B B GEORGIA N B  
FL PNHDL N A FL PENIN N A AK N SLOPE N A  
AK ALEUTIAN A A AK WESTERN B A AK INT BSN B A  
AK S INT B B AK SO COAST B B AK PNHDL B N  
 
 
 
8-14 DAY OUTLOOK TABLE  
OUTLOOK FOR NOV 24 - 30 2017  
 
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN  
WASHINGTON A N OREGON A N NRN CALIF A N  
SRN CALIF A N IDAHO A A NEVADA A N  
W MONTANA A A E MONTANA A N WYOMING A A  
UTAH A N ARIZONA A B COLORADO A N  
NEW MEXICO A B N DAKOTA A N S DAKOTA A N  
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 B MISSOURI A B  
ARKANSAS A B LOUISIANA A B WISCONSIN A N  
ILLINOIS A B MISSISSIPPI A B MICHIGAN A N  
INDIANA N B OHIO N B KENTUCKY N B  
TENNESSEE N B ALABAMA N B NEW YORK N B  
VERMONT N B NEW HAMP N B MAINE N N  
MASS N B CONN N B RHODE IS N B  
PENN N B NEW JERSEY B B W VIRGINIA B B  
MARYLAND B B DELAWARE B B VIRGINIA B B  
N CAROLINA B B S CAROLINA B B GEORGIA B B  
FL PNHDL N B FL PENIN B B AK N SLOPE N A  
AK ALEUTIAN A A AK WESTERN A A AK INT BSN B N  
AK S INT N N AK SO COAST N 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.  
 

 
 
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