984  
FXUS06 KWBC 132033  
PMDMRD  
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS  
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD  
300 PM EST MON NOVEMBER 13 2017  
 
6-10 DAY OUTLOOK FOR NOV 19 - 23 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 EASTERN CONUS WITH A BLOCKING RIDGE OVER THE DAVIS  
STRAIT. ABOVE NORMAL 500-HPA HEIGHTS ARE PREDICTED OVER WESTERN ALASKA AND  
ACROSS THE WESTERN HALF OF THE CONUS. BELOW NORMAL 500-HPA HEIGHTS ARE FORECAST  
OVER THE REMAINDER OF THE CONUS AND CENTRAL EASTERN REGION OF ALASKA.  
 
BELOW NORMAL TEMPERATURES ARE LIKELY FOR MUCH OF ALASKA, ESPECIALLY THE  
SOUTHEASTERN COAST OF THE STATE, UNDER STRONGLY NEGATIVE 500-HPA HEIGHT  
ANOMALIES AND OFFSHORE FLOW. 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 THIRD OF THE CONUS DUE TO  
ANOMALOUS NORTHERLY FLOW.  
 
ABOVE NORMAL PRECIPITATION IS FAVORED FOR NORTHWESTERN PARTS OF ALASKA AND  
ALASKA PANHANDLE, CONSISTENT WITH GEFS AND ECMWF REFORECAST TOOLS. BELOW NORMAL  
PRECIPITATION IS MOST LIKELY FOR SOUTHERN REGIONS OF ALASKA, AHEAD OF A  
PREDICTED RIDGE AND OFFSHORE FLOW. ABOVE NORMAL PRECIPITATION IS MOST LIKELY  
FOR NORTHERN AND CENTRAL 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  
NORTHEAST, DUE TO CYCLONIC FLOW. 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 20% OF TODAY'S 6Z GFS  
ENSEMBLE MEAN CENTERED ON DAY 8, 10% OF TODAY'S GFS SUPERENSEMBLE MEAN CENTERED  
ON DAY 8, 10% OF TODAY'S OPERATIONAL 0Z GFS CENTERED ON DAY 8, 40% OF TODAY'S  
0Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 8, 10% 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: ABOVE AVERAGE, 4 OUT OF 5, DUE TO  
GOOD MODEL AGREEMENT ON THE EXPECTED CIRCULATION PATTERN, AND GOOD AGREEMENT  
AMONG THE TEMPERATURE AND PRECIPITATION TOOLS.  
 
8-14 DAY OUTLOOK FOR NOV 21 - 27 2017  
 
THE OVERALL 500-HPA CIRCULATION PATTERN PREDICTED FOR THE WEEK 2 PERIOD IS  
QUITE SIMILAR TO THE 6-10 DAY PERIOD ALTHOUGH AN UPPER-LEVEL TROUGH IS FORECAST  
TO DEAMPLIFY OVER THE ALEUTIANS. 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 AT THE BEGINNING OF 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 NORTH SLOPE  
OF ALASKA. ABOVE NORMAL TEMPERATURES ARE FAVORED FOR MOST OF THE WESTERN AND  
CENTRAL CONUS, UNDER PREDICTED ABOVE NORMAL 500-HPA HEIGHTS. BELOW NORMAL  
TEMPERATURES ARE MOST LIKELY FOR MOST OF THE EASTERN CONUS IN THE WEEK 2  
PERIOD, ASSOCIATED WITH THE UPPER-LEVEL TROUGH.  
 
ABOVE NORMAL PRECIPITATION IS MOST LIKELY FOR THE NORTHWEST CONUS INTO PARTS OF  
WESTERN MONTANA, AHEAD OF A PREDICTED TROUGH. 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 NORTHERN ALASKA, UNDER PREDICTED ONSHORE FLOW.  
 
THE OFFICIAL 8-14 DAY 500-HPA HEIGHT BLEND CONSISTS OF: 15% OF TODAY'S 0Z GFS  
ENSEMBLE MEAN CENTERED ON DAY 11, 15% OF TODAY'S GFS SUPERENSEMBLE MEAN  
CENTERED ON DAY 11, 10% OF TODAY'S OPERATIONAL 0Z GFS CENTERED ON DAY 11, 50%  
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  
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:  
19661117 - 19731110 - 19701125 - 19661112 - 19641123  
 
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:  
19661116 - 19731110 - 19701125 - 19641124 - 20061121  
 
6-10 DAY OUTLOOK TABLE  
OUTLOOK FOR NOV 19 - 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 A  
W MONTANA A A E MONTANA A B WYOMING A B  
UTAH A N 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 N B  
N TEXAS N B S TEXAS N B W TEXAS A N  
MINNESOTA B B IOWA B B MISSOURI B B  
ARKANSAS N B LOUISIANA N B WISCONSIN B B  
ILLINOIS B B MISSISSIPPI B B MICHIGAN B B  
INDIANA B B OHIO B B KENTUCKY B B  
TENNESSEE B B ALABAMA B B NEW YORK B N  
VERMONT B A NEW HAMP B A MAINE B A  
MASS B N CONN B N RHODE IS B N  
PENN B N NEW JERSEY B N W VIRGINIA B B  
MARYLAND B N DELAWARE B 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 N N AK WESTERN B A AK INT BSN B N  
AK S INT B B AK SO COAST B B AK PNHDL B A  
 
 
 
8-14 DAY OUTLOOK TABLE  
OUTLOOK FOR NOV 21 - 27 2017  
 
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN  
WASHINGTON A A OREGON A A NRN CALIF A N  
SRN CALIF A B IDAHO A A NEVADA A B  
W MONTANA A N E MONTANA A N WYOMING A B  
UTAH A B ARIZONA A B COLORADO A B  
NEW MEXICO A B N DAKOTA A N S DAKOTA A B  
NEBRASKA A B KANSAS A B OKLAHOMA A B  
N TEXAS A B S TEXAS A B W TEXAS A N  
MINNESOTA A N IOWA A B MISSOURI A B  
ARKANSAS N B LOUISIANA N B WISCONSIN N B  
ILLINOIS N B MISSISSIPPI B B MICHIGAN N B  
INDIANA B B OHIO B B KENTUCKY B B  
TENNESSEE B B ALABAMA B B NEW YORK B B  
VERMONT B B NEW HAMP B B MAINE B N  
MASS B B CONN B B RHODE IS B N  
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 B B  
FL PNHDL B B FL PENIN B B AK N SLOPE A A  
AK ALEUTIAN N B AK WESTERN N A AK INT BSN B A  
AK S INT B B AK SO COAST B B AK PNHDL B 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.  
 

 
 
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