240  
FXUS06 KWBC 202033  
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 20 2017  
 
6-10 DAY OUTLOOK FOR NOV 26 - 30 2017  
 
TODAY'S DYNAMICAL MODEL SOLUTIONS ARE IN GOOD AGREEMENT ON THE 500-HPA  
CIRCULATION PATTERN FOR THE 6-10 DAY PERIOD OVER NORTH AMERICA. A RIDGE IS  
FORECAST OVER ALASKA, WHILE A TROUGH IS PREDICTED OVER THE GULF OF ALASKA,  
EXTENDING INTO THE NORTHEAST PACIFIC. ANOTHER TROUGH IS FORECAST OVER THE  
EASTERN CONUS. ABOVE NORMAL 500-HPA HEIGHTS ARE PREDICTED OVER ALASKA AND  
ACROSS THE WESTERN CONUS. BELOW NORMAL 500-HPA HEIGHTS ARE FORECAST OVER THE  
EASTERN CONUS.  
 
ABOVE NORMAL TEMPERATURES ARE FAVORED FOR MOST OF MAINLAND ALASKA AND THE  
ALEUTIANS, AS WELL AS THE WESTERN AND CENTRAL CONUS UNDER PREDICTED ABOVE  
NORMAL 500-HPA HEIGHTS. BELOW NORMAL TEMPERATURES ARE FAVORED FOR THE EASTERN  
CONUS CORRESPONDING TO THE BELOW NORMAL 500-HPA HEIGHTS AND ANOMALOUS NORTHERLY  
FLOW.  
 
ABOVE NORMAL PRECIPITATION IS FAVORED FOR WESTERN MAINLAND ALASKA AND THE  
ALEUTIANS, DUE TO THE FORECAST TROUGH UPSTREAM AND ONSHORE FLOW. BELOW NORMAL  
PRECIPITATION IS MOST LIKELY FOR EASTERN MAINLAND ALASKA AND THE PANHANDLE,  
AHEAD OF A PREDICTED RIDGE AND OFFSHORE FLOW. ABOVE NORMAL PRECIPITATION IS  
MOST LIKELY FOR THE NORTHWESTERN CONUS, NORTHERN AND CENTRAL CALIFORNIA, AND  
MUCH OF NEVADA FOR AHEAD OF THE PREDICTED TROUGH OVER THE NORTH PACIFIC.  
PROBABILITIES OF BELOW AND NEAR NORMAL PRECIPITATION ARE ELEVATED FOR MOST OF  
THE CENTRAL AND EASTERN CONUS.  
 
THE OFFICIAL 6-10 DAY 500-HPA HEIGHT BLEND CONSISTS OF 20% OF TODAY'S 0Z GFS  
ENSEMBLE MEAN CENTERED ON DAY 8, 20% OF TODAY'S 6Z GFS ENSEMBLE MEAN CENTERED  
ON DAY 8, 20% OF TODAY'S GFS SUPERENSEMBLE MEAN CENTERED ON DAY 8, 20% 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: ABOVE AVERAGE, 4 OUT OF 5, DUE TO  
GOOD MODEL AGREEMENT ON THE EXPECTED CIRCULATION PATTERN  
 
8-14 DAY OUTLOOK FOR NOV 28 - DEC 04, 2017  
 
THE OVERALL 500-HPA CIRCULATION PATTERN PREDICTED FOR THE WEEK 2 PERIOD IS  
SIMILAR TO THE 6-10 DAY PERIOD ACROSS NORTH AMERICA. 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 0Z ENSEMBLE MEAN BASED ON CONSIDERATIONS OF RECENT SKILL AND ANALOG  
CORRELATIONS.  
 
ABOVE NORMAL HEIGHTS TILT THE ODDS TO ABOVE NORMAL TEMPERATURES FOR MAINLAND  
ALASKA AND THE ALEUTIANS. NEAR TO ABOVE NORMAL HEIGHTS, ENHANCE PROBABILITIES  
OF ABOVE NORMAL TEMPERATURES FOR THE MOST OF THE CONUS EXCEPT FOR BELOW NORMAL  
TEMPERATURE IN NORTHERN NEW ENGLAND.  
 
ABOVE NORMAL PRECIPITATION IS SLIGHTLY FAVORED FOR THE GREAT BASIN, THE  
NORTHERN AND CENTRAL ROCKIES, THE NORTHERN AND CENTRAL PLAINS, MUCH OF THE  
MISSISSIPPI VALLEY, THE GREAT LAKES, AND THE OHIO AND TENNESSEE VALLEY,  
CONSISTENT TO ESTIMATES FROM THE ECMWF AND GEFS REFORECAST TOOLS. BELOW NORMAL  
PRECIPITATION IS LIKELY FOR THE NORTHWEST, PARTS OF THE SOUTHWESTERN CONUS, AND  
THE MIDDLE AND SOUTH ATLANTIC COAST STATES. EASTERN ALASKA IS FAVORED TO HAVE  
BELOW OR NEAR NORMAL PRECIPITATION, WHILE ABOVE NORMAL PRECIPITATION IS LIKELY  
FOR WESTERN MAINLAND ALASKA AND THE ALEUTIANS, UNDER PREDICTED ONSHORE AND  
CYCLONIC FLOW.  
 
THE OFFICIAL 8-14 DAY 500-HPA HEIGHT BLEND CONSISTS OF: 5% OF TODAY'S 0Z GFS  
ENSEMBLE MEAN CENTERED ON DAY 11, 20% OF TODAY'S 6Z GFS ENSEMBLE MEAN CENTERED  
ON DAY 11, 20% OF TODAY'S GFS SUPERENSEMBLE MEAN CENTERED ON DAY 11, 30% OF  
TODAY'S 0Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 11, 20% OF YESTERDAY'S 0Z  
EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 10, AND 5% OF TODAY'S 0Z CANADIAN  
ENSEMBLE MEAN CENTERED ON DAY 11  
 
FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD IS: BELOW AVERAGE, 2 OUT OF 5, DUE  
TO 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: QIN Z  
 
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:  
19701122 - 19901123 - 19541203 - 19731110 - 19711107  
 
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:  
19701121 - 19701126 - 19711106 - 19961105 - 19541202  
 
6-10 DAY OUTLOOK TABLE  
OUTLOOK FOR NOV 26 - 30 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 A WYOMING A A  
UTAH A N 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 A B W TEXAS A B  
MINNESOTA A N IOWA A B MISSOURI A B  
ARKANSAS A B LOUISIANA A B WISCONSIN N B  
ILLINOIS A B MISSISSIPPI A B MICHIGAN B B  
INDIANA N B OHIO B B KENTUCKY B B  
TENNESSEE B B ALABAMA N B NEW YORK B B  
VERMONT B B NEW HAMP B B MAINE B N  
MASS B 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 B B  
FL PNHDL B B FL PENIN B B AK N SLOPE A A  
AK ALEUTIAN A A AK WESTERN A A AK INT BSN A B  
AK S INT A N AK SO COAST A N AK PNHDL B B  
 
 
 
8-14 DAY OUTLOOK TABLE  
OUTLOOK FOR NOV 28 - DEC 04, 2017  
 
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN  
WASHINGTON N B OREGON N B NRN CALIF N N  
SRN CALIF A N IDAHO N A NEVADA A A  
W MONTANA N A E MONTANA N A WYOMING A A  
UTAH A A ARIZONA A B COLORADO A A  
NEW MEXICO A B N DAKOTA A A S DAKOTA A A  
NEBRASKA A A KANSAS A A OKLAHOMA A A  
N TEXAS A N S TEXAS A N W TEXAS A N  
MINNESOTA A A IOWA A A MISSOURI A A  
ARKANSAS A A LOUISIANA A B WISCONSIN A A  
ILLINOIS A A MISSISSIPPI A B MICHIGAN A A  
INDIANA A A OHIO A A KENTUCKY A A  
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 A N  
MARYLAND N B DELAWARE N B VIRGINIA N B  
N CAROLINA N B S CAROLINA A B GEORGIA A B  
FL PNHDL A B FL PENIN A B AK N SLOPE A N  
AK ALEUTIAN A A AK WESTERN A A AK INT BSN A A  
AK S INT A A AK SO COAST A A 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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