665  
FXUS06 KWBC 092002  
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 09 2017  
 
6-10 DAY OUTLOOK FOR NOV 15 - 19 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. ANOTHER  
TROUGH IS FORECAST OVER THE WESTERN ATLANTIC. ABOVE NORMAL 500-HPA HEIGHTS ARE  
PREDICTED OVER WESTERN ALASKA AND IN AN AREA STRETCHING FROM THE SOUTHWEST  
ACROSS THE CENTRAL AND SOUTHERN PLAINS TO THE MISSISSIPPI VALLEY REGION. NEAR  
TO BELOW NORMAL 500-HPA HEIGHTS ARE FORECAST OVER THE REMAINDER OF THE CONUS  
AND ALASKA.  
 
ABOVE NORMAL TEMPERATURES ARE MOST LIKELY FOR THE WESTERN ALEUTIANS AND PARTS  
OF THE NORTH SLOPE OF ALASKA UNDER LARGE POSITIVE 500-HPA HEIGHT ANOMALIES  
ASSOCIATED WITH A PREDICTED RIDGE. 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 AND OFFSHORE FLOW.  
PROBABILITIES OF BELOW NORMAL TEMPERATURES ARE ALSO ENHANCED FOR PARTS OF  
WASHINGTON AND MONTANA, 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 REGION UNDER PREDICTED ABOVE NORMAL 500-HPA HEIGHTS. ABOVE NORMAL  
TEMPERATURES ARE FAVORED FOR THE GREAT LAKES REGION, CONSISTENT WITH CALIBRATED  
REFORECAST TEMPERATURE TOOLS FROM GFS AND ECMWF ENSEMBLE FORECASTS. NEAR NORMAL  
TEMPERATURES ARE MORE LIKELY FOR PARTS OF THE EASTERN CONUS DUE TO A VARIABLE  
TEMPERATURE PATTERN.  
 
BELOW NORMAL PRECIPITATION IS MOST LIKELY FOR INTERIOR AND SOUTHERN REGIONS OF  
ALASKA, AHEAD OF A PREDICTED RIDGE AND OFFSHORE FLOW. 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 GREAT LAKES, PARTS OF THE NORTHEAST,  
THE UPPER AND MIDDLE MISSISSIPPI VALLEY, THE OHIO VALLEY, AND THE TENNESSEE  
VALLEY. BELOW NORMAL PRECIPITATION IS FORECAST FOR MOST OF THE REMAINING AREAS  
OF THE CONUS, EXCEPT FOR CLIMATOLOGICALLY DRY AREAS OF THE SOUTHWEST WHERE NEAR  
NORMAL PRECIPITATION IS INDICATED.  
 
THE OFFICIAL 6-10 DAY 500-HPA HEIGHT BLEND CONSISTS OF 10% OF TODAY'S 0Z GFS  
ENSEMBLE MEAN CENTERED ON DAY 8, 10% OF TODAY'S 6Z GFS ENSEMBLE MEAN CENTERED  
ON DAY 8, 10% OF TODAY'S GFS SUPERENSEMBLE MEAN CENTERED ON DAY 8, 5% OF  
TODAY'S OPERATIONAL 0Z GFS 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,  
AND 20% 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  
GOOD MODEL AGREEMENT ON THE EXPECTED CIRCULATION PATTERN, AND FAIR AGREEMENT  
AMONG THE TEMPERATURE AND PRECIPITATION TOOLS.  
 
8-14 DAY OUTLOOK FOR NOV 17 - 23 2017  
 
THE OVERALL 500-HPA CIRCULATION PATTERN PREDICTED FOR THE WEEK 2 PERIOD IS  
QUITE SIMILAR TO THE 6-10 DAY PERIOD. THE ENSEMBLE SPAGHETTI DIAGRAMS INDICATE  
MODERATE TO LARGE SPREAD ACROSS THE MAJORITY OF THE FORECAST DOMAIN. THE  
GREATEST WEIGHT WAS GIVEN TO THE ECMWF ENSEMBLE MEAN BASED ON CONSIDERATIONS OF  
RECENT SKILL AND ANALOG CORRELATIONS.THE ARCTIC OSCILLATION INDEX IS FORECAST  
TO BECOME LARGELY NEGATIVE BY THE GFS MODEL DURING WEEK2.  
 
BELOW NORMAL TEMPERATURES ARE MOST LIKELY FOR A LARGE AREA OF SOUTHEASTERN  
ALASKA WITH PREDICTED BELOW NORMAL 500-HPA HEIGHTS AND PERSISTENT OFFSHORE  
FLOW. ABOVE NORMAL TEMPERATURES REMAIN MOST LIKELY FOR PARTS OF THE WESTERN  
ALEUTIANS, AS WELL AS 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 FOR  
MOST OF THE WESTERN AND CENTRAL CONUS, UNDER PREDICTED ABOVE NORMAL 500-HPA  
HEIGHTS AND MEAN ZONAL FLOW. BELOW NORMAL TEMPERATURES ARE MOST LIKELY FOR PART  
OF THE SOUTHEAST AND THE MIDDLE ATLANTIC IN THE WEEK 2 PERIOD, UNDER  
ANOMALOUSLY NORTHERLY FLOW.  
 
ABOVE NORMAL PRECIPITATION IS MOST LIKELY FOR THE NORTHWEST CONUS INTO PARTS OF  
WESTERN MONTANA, AHEAD OF A PREDICTED TROUGH, AND FROM NORTHERN PARTS OF THE  
GREAT LAKES REGION INTO THE NORTHEAST, WITH PREDOMINANT TROUGHING IN MODEL  
ENSEMBLE MEMBERS. ALSO, THE EVOLVING PATTERN FAVORS LAKE-EFFECT SNOW. 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: 10% OF TODAY'S 0Z GFS  
ENSEMBLE MEAN CENTERED ON DAY 11, 10% OF TODAY'S 6Z GFS ENSEMBLE MEAN CENTERED  
ON DAY 11, 10% OF TODAY'S GFS SUPERENSEMBLE MEAN CENTERED ON DAY 11, 40% OF  
TODAY'S 0Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 11, AND 30% 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: LUKE H  
 
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:  
20031106 - 19811025 - 19661112 - 19911022 - 19651111  
 
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 - 19811025 - 19651112 - 20031106 - 19651107  
 
6-10 DAY OUTLOOK TABLE  
OUTLOOK FOR NOV 15 - 19 2017  
 
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN  
WASHINGTON N A OREGON N A NRN CALIF N A  
SRN CALIF A N IDAHO N A NEVADA A N  
W MONTANA B A E MONTANA N A WYOMING A B  
UTAH A B ARIZONA A N COLORADO A B  
NEW MEXICO A N 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 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 A KENTUCKY A A  
TENNESSEE A N ALABAMA A B NEW YORK N A  
VERMONT N A 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 N  
N CAROLINA N B S CAROLINA N B GEORGIA A B  
FL PNHDL A B FL PENIN N 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  
 
 
 
8-14 DAY OUTLOOK TABLE  
OUTLOOK FOR NOV 17 - 23 2017  
 
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN  
WASHINGTON A A OREGON A A NRN CALIF A A  
SRN CALIF A N IDAHO A A NEVADA A B  
W MONTANA A A E MONTANA A N 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 N N IOWA A B MISSOURI A B  
ARKANSAS A B LOUISIANA A B WISCONSIN N N  
ILLINOIS N B MISSISSIPPI A B MICHIGAN N N  
INDIANA N N OHIO N N KENTUCKY N N  
TENNESSEE N N ALABAMA N 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 B N  
MARYLAND N N DELAWARE N N VIRGINIA B B  
N CAROLINA B B S CAROLINA B B GEORGIA B B  
FL PNHDL B B FL PENIN B 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  
 
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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