997  
FXUS06 KWBC 072018  
PMDMRD  
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS  
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD  
300 PM EST TUE NOVEMBER 07 2017  
 
6-10 DAY OUTLOOK FOR NOV 13 - 17 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, TO THE WEST  
OF THE ALASKA PANHANDLE AND PACIFIC NORTHWEST. ABOVE NORMAL 500-HPA HEIGHTS ARE  
PREDICTED IN AN AREA STRETCHING FROM THE SOUTHWEST ACROSS THE CENTRAL AND  
SOUTHERN PLAINS INTO THE NORTHEAST. A RELATIVE TROUGH AND NEAR TO BELOW NORMAL  
500-HPA HEIGHTS ARE FORECAST OFF OF THE ATLANTIC COAST. ENSEMBLE SPREAD IS  
RELATIVELY LOW INDICATING GOOD AGREEMENT AMONG MEMBERS ON THE CIRCULATION  
PATTERN.  
 
ABOVE NORMAL TEMPERATURES ARE MOST LIKELY FOR THE WEST COAST OF ALASKA AND THE  
ALEUTIANS WITH POSITIVE 500-HPA HEIGHT ANOMALIES UNDER THE PREDICTED RIDGE, AND  
FOR THE NORTH SLOPE, WITH ABOVE NORMAL SEA SURFACE TEMPERATURES AND NORTHERLY  
FLOW. BELOW NORMAL TEMPERATURES ARE LIKELY FOR SOUTHEASTERN ALASKA, INCLUDING  
THE ALASKA PANHANDLE, AS WELL AS PARTS OF THE PACIFIC NORTHWEST, UNDER BELOW  
NORMAL 500-HPA HEIGHTS ASSOCIATED WITH A PREDICTED TROUGH. ABOVE NORMAL  
TEMPERATURES ARE MOST LIKELY FOR MUCH OF THE REMAINING AREAS OF THE CONUS UNDER  
PREDICTED ABOVE NORMAL 500-HPA HEIGHTS. NEAR NORMAL TEMPERATURES ARE MORE  
LIKELY FOR PARTS OF THE EASTERN CONUS WITH ANOMALOUSLY NORTHERLY FLOW TO THE  
WEST PREDICTED TROUGHING IN THE 6-10 DAY PERIOD.  
 
ABOVE NORMAL PRECIPITATION IS LIKELY FOR NORTHERN ALASKA AND THE ALASKA  
INTERIOR, WITH PREDICTED NORTHERLY MID-LEVEL FLOW, WHILE BELOW NORMAL  
PRECIPITATION IS MORE LIKELY FOR SOUTHERN ALASKA. ABOVE NORMAL PRECIPITATION IS  
MOST LIKELY FOR NORTHERN CALIFORNIA AND THE NORTHWEST REGION OF THE CONUS AHEAD  
OF THE PREDICTED TROUGH OVER THE NORTH PACIFIC. THE PROBABILITIES OF ABOVE  
NORMAL PRECIPITATION ARE ELEVATED FOR THE 6-10 DAY PERIOD OVER THE WESTERN  
GREAT LAKES REGION AND PARTS OF THE NORTHEAST.  
 
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, 4 OUT OF 5, DUE TO  
GOOD MODEL AGREEMENT ON THE EXPECTED CIRCULATION PATTERN, LOW ENSEMBLE MEMBER  
SPREAD, AND FAIRLY GOOD AGREEMENT AMONG THE TEMPERATURE AND PRECIPITATION TOOLS.  
 
8-14 DAY OUTLOOK FOR NOV 15 - 21 2017  
 
THE OVERALL 500-HPA CIRCULATION PATTERN PREDICTED FOR THE WEEK 2 PERIOD CHANGES  
LITTLE FROM THE 6-10 DAY PERIOD FORECAST, HOWEVER, ENSEMBLE SPREAD INCREASES  
SUBSTANTIALLY, INDICATING GREATER FORECAST UNCERTAINTY. SOME RETROGRESSION OF A  
PREDICTED TROUGH OVER SOUTHEASTERN ALASKA 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, RELATED TO INCREASING SPREAD  
AMONG ENSEMBLE MEMBERS.  
 
BELOW NORMAL TEMPERATURES ARE MOST LIKELY FOR A LARGER AREA OF SOUTHEASTERN  
ALASKA WITH DECREASING PREDICTED 500-HPA HEIGHTS. ABOVE NORMAL TEMPERATURES  
REMAIN MOST LIKELY FOR PARTS OF THE WESTERN ALEUTIANS, THE NORTHWEST COAST, AND  
THE NORTH SLOPE. BELOW NORMAL TEMPERATURES REMAIN MOST LIKELY FOR PARTS OF THE  
PACIFIC NORTHWEST WITH PREDICTED BELOW NORMAL 500-HPA HEIGHTS. ABOVE NORMAL  
TEMPERATURES ARE LIKELY FROM CENTRAL AND SOUTHERN CALIFORNIA, ACROSS THE  
SOUTHWEST AND THE CENTRAL AND SOUTHERN PLAINS STATES, AND FOR THE EASTERN THIRD  
OF THE CONUS, UNDER PREDICTED ABOVE NORMAL 500-HPA HEIGHTS AND MEAN ZONAL FLOW.  
THE PROBABILITIES OF ABOVE NORMAL TEMPERATURES HAVE INCREASED FOR THE  
NORTHEAST, WHERE MODEL FORECASTS INDICATE LESS OF A NORTHERLY COMPONENT TO THE  
MEAN MID-LEVEL CIRCULATION IN THE WEEK 2 PERIOD. NEAR TO BELOW NORMAL  
TEMPERATURES ARE INDICATED FOR PARTS OF THE NORTHERN PLAINS AND WESTERN GREAT  
LAKES REGION, UNDER PREDICTED 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, 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: 10% OF TODAY'S 0Z GFS  
ENSEMBLE MEAN CENTERED ON DAY 11, 25% OF TODAY'S 6Z GFS ENSEMBLE MEAN CENTERED  
ON DAY 11, 40% OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 11, AND 25%  
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 - 20031103 - 19711102 - 19861115 - 19821018  
 
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:  
19911022 - 19661111 - 19711102 - 19851110 - 19861114  
 
6-10 DAY OUTLOOK TABLE  
OUTLOOK FOR NOV 13 - 17 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 B  
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 B IOWA A B MISSOURI A B  
ARKANSAS A B LOUISIANA A B WISCONSIN A A  
ILLINOIS A B MISSISSIPPI A B MICHIGAN A A  
INDIANA A N OHIO N N KENTUCKY N B  
TENNESSEE N B ALABAMA A B NEW YORK N N  
VERMONT N A NEW HAMP N A MAINE N A  
MASS N A CONN N A RHODE IS N A  
PENN N N NEW JERSEY N A W VIRGINIA N B  
MARYLAND N N DELAWARE N N VIRGINIA N B  
N CAROLINA N B S CAROLINA N B GEORGIA N B  
FL PNHDL A B FL PENIN A B AK N SLOPE A A  
AK ALEUTIAN A B AK WESTERN N B AK INT BSN B N  
AK S INT B B AK SO COAST B B AK PNHDL B B  
 
 
 
8-14 DAY OUTLOOK TABLE  
OUTLOOK FOR NOV 15 - 21 2017  
 
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN  
WASHINGTON B A OREGON N A NRN CALIF N A  
SRN CALIF A B IDAHO N A NEVADA N B  
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 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 N LOUISIANA A B WISCONSIN N A  
ILLINOIS A N MISSISSIPPI A B MICHIGAN N A  
INDIANA A A OHIO A A KENTUCKY A A  
TENNESSEE A N ALABAMA A B NEW YORK A N  
VERMONT A N NEW HAMP A N MAINE A N  
MASS A N CONN A N RHODE IS A N  
PENN A N NEW JERSEY A N W VIRGINIA A N  
MARYLAND A N DELAWARE A N VIRGINIA A B  
N CAROLINA A B S CAROLINA A B GEORGIA A B  
FL PNHDL A B FL PENIN A B AK N SLOPE N A  
AK ALEUTIAN B B AK WESTERN B B AK INT BSN B N  
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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