770  
FXUS06 KWBC 011902  
PMDMRD  
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS  
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD  
300 PM EDT WED NOVEMBER 01 2017  
 
6-10 DAY OUTLOOK FOR NOV 07 - 11 2017  
 
TODAY'S ENSEMBLE MEAN SOLUTIONS ARE IN GOOD AGREEMENT IN THEIR PREDICTION OF  
THE FLOW PATTERN OVER MUCH OF THE FORECAST DOMAIN. A STRONG RIDGE IS FORECAST  
OVER MAINLAND ALASKA, WHILE A TROUGH IS EXPECTED OVER THE ALASKA PANHANDLE. A  
DEEP TROUGH IS EXPECTED NORTH OF HUDSON BAY EXTENDING SOUTHEASTWARD OVER  
NORTHEASTERN NORTH AMERICA, WHILE RIDGES ARE ANTICIPATED OVER THE CENTRAL  
ATLANTIC AND ACROSS MUCH OF THE SOUTHERN TIER OF THE U.S. FAST ZONAL FLOW IS  
FORECAST FOR MUCH OF THE CONUS.  
 
THE ENSEMBLE SPAGHETTI DIAGRAMS INDICATE LOW TO MODERATE SPREAD FOR MOST OF THE  
CONUS, WITH MODERATE TO LARGE SPREAD DEPICTED FOR THE EASTERN PACIFIC AND  
ALASKA. THE PNA INDEX, WHICH RECENTLY HAS BEEN NEGATIVE, IS FORECAST TO REMAIN  
NEGATIVE THROUGH DAY 14, WHILE THE AO INDEX WHICH HAS RECENTLY BEEN NEAR ZERO  
IS ANTICIPATED TO BE POSITIVE AT DAY 7, REMAIN POSITIVE AT DAY 10, AND BE NEAR  
ZERO OR WEAKLY POSITIVE AT DAY 14. TODAYS BLENDED HEIGHT CHART INDICATES NEAR  
TO BELOW NORMAL HEIGHTS FOR THE NORTHWEST CONUS AND ACROSS MUCH OF THE NORTHERN  
TIER OF THE CONUS, WHILE NEAR TO ABOVE NORMAL HEIGHTS ARE ANTICIPATED FOR THE  
REMAINDER OF THE FORECAST DOMAIN. POSITIVE HEIGHT ANOMALIES EXCEEDING 250  
METERS ARE FORECAST OVER THE ALEUTIANS. TELECONNECTIONS ON THIS AREA OF  
POSITIVE HEIGHT ANOMALIES YIELDS A HEIGHT PATTERN SIMILAR TO THAT FORECAST BY  
THE DYNAMICAL MODELS, ALTHOUGH THE TELECONNECTIONS INDICATE A STRONGER TROUGH  
OVER NORTHEASTERN NORTH AMERICA.  
 
ABOVE NORMAL HEIGHTS TILT THE ODDS TO ABOVE NORMAL TEMPERATURES FOR MUCH OF THE  
SOUTHERN AND EASTERN CONUS, WHILE NEAR TO BELOW NORMAL HEIGHTS FAVOR NEAR TO  
BELOW NORMAL TEMPERATURES FOR THE NORTHERN TIER OF THE CONUS, THE NORTHWESTERN  
PORTION OF THE U.S., AND PARTS OF CALIFORNIA. ABOVE NORMAL HEIGHTS ENHANCE  
PROBABILITIES FOR ABOVE NORMAL TEMPERATURES FOR NORTHERN ALASKA AND THE  
ALEUTIANS, WHILE ANOMALOUS NORTHEASTERLY FLOW TILTS THE ODDS TO BELOW NORMAL  
TEMPERATURES FOR THE ALASKA PANHANDLE.  
 
CYCLONIC FLOW AND/OR BELOW NORMAL HEIGHTS FAVOR ABOVE NORMAL PRECIPITATION FOR  
PARTS OF THE NORTHEAST, MID-ATLANTIC, OHIO AND TENNESSEE VALLEYS, AND NORTHWEST  
CONUS. ABOVE NORMAL HEIGHTS TILT THE ODDS TO BELOW NORMAL PRECIPITATION ACROSS  
MUCH OF THE SOUTHERN CONUS. WEAK ANTICYCLONIC FLOW ENHANCES PROBABILITIES FOR  
BELOW NORMAL PRECIPITATION FOR PARTS OF THE INTERIOR WEST AND NORTHERN PLAINS.  
BELOW NORMAL PRECIPITATION IS ALSO FAVORED FOR MUCH OF SOUTHERN ALASKA DUE TO  
EXPECTED OFFSHORE FLOW. HOWEVER, ABOVE NORMAL PRECIPITATION PROBABILITIES ARE  
ENHANCED FOR NORTHERN MAINLAND ALASKA UNDERNEATH WESTERLY LOW LEVEL FLOW.  
 
TODAY'S OFFICIAL 500-HPA BLEND CONSISTS OF 10% OF TODAY'S 0Z GFS ENSEMBLE MEAN  
CENTERED ON DAY 8, 20% OF TODAY'S 6Z GFS ENSEMBLE MEAN CENTERED ON DAY 8, 25%  
OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 8, 10% OF YESTERDAY'S 12Z  
EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 7, 5% OF TODAY'S OPERATIONAL 0Z ECMWF  
CENTERED ON DAY 8, 5% OF YESTERDAY'S OPERATIONAL 12Z ECMWF CENTERED ON DAY 7,  
10% OF TODAY'S 0Z CANADIAN ENSEMBLE MEAN CENTERED ON DAY 8, AND 15% OF  
YESTERDAY'S 12Z CANADIAN ENSEMBLE MEAN CENTERED ON DAY 7  
 
 
FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: ABOVE AVERAGE, 4 OUT OF 5, DUE TO  
GOOD MODEL AGREEMENT ON THE EXPECTED FLOW PATTERN OVER MUCH OF THE FORECAST  
DOMAIN.  
 
8-14 DAY OUTLOOK FOR NOV 09 - 15 2017  
 
DURING THE WEEK-2 PERIOD, LITTLE OVERALL CHANGE IS PREDICTED FROM THE  
CIRCULATION PATTERN FORECAST DURING THE 6-10 DAY PERIOD. A SLIGHT PROGRESSION  
OF THE TROUGH PREDICTED OVER NORTHEAST NORTH AMERICA AND A SLIGHT SUPPRESSION  
OF THE RIDGE OVER THE SOUTHERN CONUS ARE INDICATED. HEIGHTS ARE EXPECTED TO BE  
NEAR TO BELOW NORMAL FOR THE NORTHWESTERN CONUS AND NEAR TO ABOVE NORMAL OVER  
THE REMAINDER OF THE FORECAST DOMAIN. THE ENSEMBLE SPAGHETTI DIAGRAMS INDICATE  
MODERATE SPREAD FOR MOST OF THE CONUS, WITH MODERATE TO LARGE SPREAD DEPICTED  
FOR THE EASTERN PACIFIC AND ALASKA.  
 
NEAR TO BELOW NORMAL HEIGHTS FAVOR NEAR TO BELOW NORMAL TEMPERATURES FOR MUCH  
OF THE NORTHERN TIER OF THE CONUS, PARTS OF NORTHERN CALIFORNIA AND THE ALASKA  
PANHANDLE. NEAR TO ABOVE NORMAL HEIGHTS TILT THE ODDS TO NEAR TO ABOVE NORMAL  
TEMPERATURES FOR THE REMAINDER OF THE CONUS, NORTHERN ALASKA, AND THE ALEUTIANS.  
 
CYCLONIC FLOW AND THE POTENTIAL FOR LAKE EFFECT PRECIPITATION ENHANCES  
PROBABILITIES FOR ABOVE NORMAL PRECIPITATION FOR THE GREAT LAKES, PARTS OF THE  
OHIO AND TENNESSEE VALLEYS, AND MIDDLE AND LOWER MISSISSIPPI VALLEYS. ABOVE  
NORMAL HEIGHTS TILT THE ODDS TO BELOW NORMAL PRECIPITATION FOR PARTS OF THE  
GULF COAST, SOUTHEAST CONUS, THE HIGH PLAINS, AND INTERIOR SOUTHWEST CONUS. THE  
TROUGH FORECAST NEAR THE ALASKA PANHANDLE FAVORS ABOVE NORMAL PRECIPITATION FOR  
THE NORTHWESTERN LOWER 48 STATES. WESTERLY SURFACE FLOW ENHANCES PROBABILITIES  
FOR ABOVE NORMAL PRECIPITATION FOR NORTHERN ALASKA WHILE ABOVE NORMAL HEIGHTS  
TILT THE ODDS TO BELOW NORMAL PRECIPITATION FOR SOUTHERN MAINLAND ALASKA, THE  
ALEUTIANS, AND THE ALASKA PANHANDLE.  
 
THE OFFICIAL 8-14 DAY HEIGHT PROG CONSISTS OF: 15% OF TODAY'S 0Z GFS ENSEMBLE  
MEAN CENTERED ON DAY 11, 20% OF TODAY'S 6Z GFS ENSEMBLE MEAN CENTERED ON DAY  
11, 15% OF TODAY'S GFS SUPERENSEMBLE MEAN CENTERED ON DAY 11, 25% OF TODAY'S 0Z  
EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 11, 15% OF YESTERDAY'S 12Z EUROPEAN  
ENSEMBLE MEAN CENTERED ON DAY 10, 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 FAIR AGREEMENT AMONG THE ENSEMBLE MEAN SOLUTIONS ON THE 500-HPA PATTERN.  
 
FORECASTER: RANDY S  
 
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:  
19811022 - 20031028 - 19591110 - 19661104 - 19861111  
 
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:  
19811021 - 19661103 - 20031029 - 19591110 - 19891101  
 
6-10 DAY OUTLOOK TABLE  
OUTLOOK FOR NOV 07 - 11 2017  
 
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN  
WASHINGTON B A OREGON B A NRN CALIF B A  
SRN CALIF B N IDAHO B A NEVADA B B  
W MONTANA B B E MONTANA B B WYOMING B B  
UTAH N B ARIZONA A N COLORADO A N  
NEW MEXICO A B N DAKOTA B B S DAKOTA B B  
NEBRASKA B N KANSAS B N OKLAHOMA N N  
N TEXAS A B S TEXAS A B W TEXAS A B  
MINNESOTA B B IOWA B N MISSOURI B A  
ARKANSAS A N LOUISIANA A B WISCONSIN B B  
ILLINOIS N A MISSISSIPPI A B MICHIGAN B N  
INDIANA N A OHIO A A KENTUCKY A A  
TENNESSEE A N ALABAMA A B NEW YORK N A  
VERMONT N A NEW HAMP A A MAINE N A  
MASS A A CONN A A RHODE IS A A  
PENN A A NEW JERSEY A A W VIRGINIA A A  
MARYLAND A A DELAWARE A A VIRGINIA A A  
N CAROLINA A N S CAROLINA A B GEORGIA A B  
FL PNHDL A B FL PENIN A B AK N SLOPE A A  
AK ALEUTIAN A B AK WESTERN A A AK INT BSN A A  
AK S INT N B AK SO COAST N B AK PNHDL B B  
 
 
 
8-14 DAY OUTLOOK TABLE  
OUTLOOK FOR NOV 09 - 15 2017  
 
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN  
WASHINGTON B A OREGON B A NRN CALIF B A  
SRN CALIF A N IDAHO N A NEVADA A N  
W MONTANA B A E MONTANA B N WYOMING N B  
UTAH A B ARIZONA A B COLORADO A B  
NEW MEXICO A B N DAKOTA B N S DAKOTA B N  
NEBRASKA N B KANSAS A B OKLAHOMA A N  
N TEXAS A N S TEXAS A B W TEXAS A B  
MINNESOTA B N IOWA N N MISSOURI A A  
ARKANSAS A N LOUISIANA A B WISCONSIN N N  
ILLINOIS N A MISSISSIPPI A B MICHIGAN N A  
INDIANA N A OHIO N A KENTUCKY N A  
TENNESSEE A N ALABAMA A B NEW YORK N A  
VERMONT N N NEW HAMP N N MAINE N N  
MASS N N CONN N N RHODE IS N N  
PENN N A NEW JERSEY N N W VIRGINIA N N  
MARYLAND N N DELAWARE N N VIRGINIA N N  
N CAROLINA N B S CAROLINA A B GEORGIA A B  
FL PNHDL A B FL PENIN A B AK N SLOPE A A  
AK ALEUTIAN A B AK WESTERN A N AK INT BSN A N  
AK S INT N B AK SO COAST N 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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