744  
FXUS06 KWBC 031942  
PMDMRD  
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS  
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD  
300 PM EDT FRI NOVEMBER 03 2017  
 
6-10 DAY OUTLOOK FOR NOV 09 - 13 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 THE ALEUTIANS/BERING SEA, WHILE A TROUGH IS EXPECTED NEAR 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 CENTERED OVER WESTERN MEXICO. 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 STRONGLY NEGATIVE, IS FORECAST  
TO REMAIN NEGATIVE THROUGH DAY 14, WHILE THE AO INDEX WHICH HAS RECENTLY BEEN  
POSITIVE IS ANTICIPATED TO REMAIN POSITIVE THROUGH DAY 7, BE NEAR ZERO AT DAY  
10, AND BE WEAKLY NEGATIVE BY DAY 14. TODAYS BLENDED HEIGHT CHART INDICATES  
NEAR TO BELOW NORMAL HEIGHTS FOR THE NORTHWEST CONUS, WHILE NEAR TO ABOVE  
NORMAL HEIGHTS ARE ANTICIPATED FOR THE REMAINDER OF THE FORECAST DOMAIN.  
POSITIVE HEIGHT ANOMALIES EXCEEDING 300 METERS ARE FORECAST OVER THE BERING  
SEA. TELECONNECTIONS ON THIS AREA OF POSITIVE HEIGHT ANOMALIES YIELDS A HEIGHT  
PATTERN VERY SIMILAR TO THAT FORECAST BY THE DYNAMICAL MODELS.  
 
ABOVE NORMAL HEIGHTS TILT THE ODDS TO ABOVE NORMAL TEMPERATURES FOR MUCH OF THE  
SOUTHWESTERN AND SOUTH-CENTRAL CONUS, WHILE NEAR TO BELOW NORMAL HEIGHTS FAVOR  
NEAR TO BELOW NORMAL TEMPERATURES FOR THE NORTHERN TIER OF THE CONUS. COLD AIR  
DAMMING ASSOCIATED WITH SURFACE HIGH PRESSURE OVER THE NORTHEAST TILTS THE ODDS  
TO BELOW NORMAL TEMPERATURES FOR MUCH OF THE EASTERN CONUS EAST OF THE  
APPALACHIANS. ABOVE NORMAL HEIGHTS FAVOR ABOVE NORMAL TEMPERATURES FOR NORTHERN  
AND CENTRAL MAINLAND ALASKA AND THE ALEUTIANS, WHILE ANOMALOUS NORTHEASTERLY  
FLOW TILTS THE ODDS TO BELOW NORMAL TEMPERATURES FOR SOUTHEASTERN MAINLAND  
ALASKA AND THE ALASKA PANHANDLE.  
 
ABOVE NORMAL HEIGHTS TILT THE ODDS TO NEAR TO BELOW NORMAL PRECIPITATION ACROSS  
MUCH OF THE CONUS AND FOR MOST OF SOUTHERN ALASKA AND THE ALEUTIANS. HOWEVER,  
ABOVE NORMAL PRECIPITATION PROBABILITIES ARE ENHANCED FOR NORTHERN MAINLAND  
ALASKA UNDERNEATH WESTERLY LOW LEVEL FLOW. THE TROUGH NEAR THE THE ALASKA  
PANHANDLE FAVORS ABOVE NORMAL PRECIPITATION FOR THE NORTHWEST CONUS.  
 
THE OFFICIAL 6-10 DAY 500-HPA HEIGHT BLEND CONSISTS OF 20% OF TODAY'S 0Z GFS  
ENSEMBLE MEAN CENTERED ON DAY 8, 10% OF TODAY'S 6Z GFS ENSEMBLE MEAN CENTERED  
ON DAY 8, 20% OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 8, 30% OF  
YESTERDAY'S 12Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 7, 10% OF TODAY'S 0Z  
CANADIAN ENSEMBLE MEAN CENTERED ON DAY 8, AND 10% OF YESTERDAY'S 12Z CANADIAN  
ENSEMBLE MEAN CENTERED ON DAY 7  
 
 
FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: ABOUT AVERAGE, 3 OUT OF 5, DUE TO  
GOOD MODEL AGREEMENT ON THE EXPECTED CIRCULATION PATTERN OVER MUCH OF THE  
FORECAST DOMAIN OFFSET BY THE EXPECTATION OF A MOSTLY ZONAL FLOW REGIME ACROSS  
THE CONUS.  
 
8-14 DAY OUTLOOK FOR NOV 11 - 17 2017  
 
DURING THE WEEK-2 PERIOD, LITTLE OVERALL CHANGE IS ANTICIPATED TO THE PREDICTED  
MID-LEVEL FLOW PATTERN FROM THAT FORECAST FOR THE 6-10 DAY PERIOD. 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 TO LARGE SPREAD FOR THE MAJORITY OF THE FORECAST  
DOMAIN.  
 
NEAR TO BELOW NORMAL HEIGHTS FAVORS NEAR TO BELOW NORMAL TEMPERATURES FOR PARTS  
OF THE NORTHWESTERN CONUS. ANOMALOUS NORTHEASTERLY FLOW TILTS THE ODDS TO BELOW  
NORMAL TEMPERATURES FOR THE ALASKA PANHANDLE. NEAR TO ABOVE NORMAL HEIGHTS  
ENHANCE PROBABILITIES FOR NEAR TO ABOVE NORMAL TEMPERATURES FOR THE REMAINDER  
OF THE CONUS, NORTHERN ALASKA, AND THE ALEUTIANS.  
 
SOUTHWESTERLY FLOW AT THE SURFACE FAVORS ABOVE NORMAL PRECIPITATION FOR PARTS  
OF THE CENTRAL CONUS AND GREAT LAKES. ABOVE NORMAL HEIGHTS TILT THE ODDS TO  
BELOW NORMAL PRECIPITATION FOR PARTS OF THE GULF COAST, THE SOUTHEAST CONUS,  
AND THE INTERIOR WESTERN CONUS. THE TROUGH FORECAST NEAR THE ALASKA PANHANDLE  
FAVORS ABOVE NORMAL PRECIPITATION FOR THE NORTHWESTERN CONUS, PARTS OF NORTHERN  
AND CENTRAL CALIFORNIA, AND EXTREME NORTHERN SECTIONS OF THE NORTHERN PLAINS.  
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 500-HPA HEIGHT BLEND CONSISTS OF: 10% OF TODAY'S 0Z GFS  
ENSEMBLE MEAN CENTERED ON DAY 11, 10% OF TODAY'S GFS SUPERENSEMBLE MEAN  
CENTERED ON DAY 11, 25% OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY  
11, 30% OF YESTERDAY'S 12Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 10, 10% OF  
TODAY'S 0Z CANADIAN ENSEMBLE MEAN CENTERED ON DAY 11, AND 15% OF YESTERDAY'S  
12Z CANADIAN ENSEMBLE MEAN CENTERED ON DAY 10  
 
FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD IS: BELOW AVERAGE, 2 OUT OF 5, DUE  
TO FAIR AGREEMENT AMONG THE ENSEMBLE MEAN SOLUTIONS ON THE 500-HPA PATTERN  
OFFSET BY MODERATE TO LARGE SPREAD AMONG THE ENSEMBLE MEMBERS.  
 
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:  
20031029 - 19911020 - 19811023 - 19861107 - 19851109  
 
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:  
20031030 - 19911021 - 19861109 - 19811022 - 19851109  
 
6-10 DAY OUTLOOK TABLE  
OUTLOOK FOR NOV 09 - 13 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 A A  
W MONTANA B A E MONTANA B N WYOMING N N  
UTAH A B ARIZONA A N COLORADO A B  
NEW MEXICO A B N DAKOTA B N S DAKOTA N B  
NEBRASKA A B KANSAS A B OKLAHOMA A B  
N TEXAS A B S TEXAS A N W TEXAS A B  
MINNESOTA B N IOWA N B MISSOURI A B  
ARKANSAS A B LOUISIANA A B WISCONSIN N N  
ILLINOIS A B MISSISSIPPI A B MICHIGAN N B  
INDIANA N B OHIO N B KENTUCKY N B  
TENNESSEE N B ALABAMA A B NEW YORK N B  
VERMONT B B NEW HAMP B N MAINE B N  
MASS B N CONN B N RHODE IS B N  
PENN N B NEW JERSEY B N W VIRGINIA N B  
MARYLAND B N DELAWARE B N VIRGINIA B N  
N CAROLINA B N S CAROLINA B N GEORGIA N N  
FL PNHDL A B FL PENIN N N AK N SLOPE A A  
AK ALEUTIAN A B AK WESTERN A N AK INT BSN A A  
AK S INT N B AK SO COAST B B AK PNHDL B B  
 
 
 
8-14 DAY OUTLOOK TABLE  
OUTLOOK FOR NOV 11 - 17 2017  
 
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN  
WASHINGTON B A OREGON B A NRN CALIF N A  
SRN CALIF A N IDAHO N A NEVADA A N  
W MONTANA B A E MONTANA N N WYOMING A B  
UTAH A B ARIZONA A B COLORADO A B  
NEW MEXICO A B N DAKOTA N N S DAKOTA A N  
NEBRASKA A A KANSAS A A OKLAHOMA A N  
N TEXAS A B S TEXAS A B W TEXAS A N  
MINNESOTA A A IOWA A A MISSOURI A A  
ARKANSAS A B LOUISIANA A B WISCONSIN A A  
ILLINOIS A A MISSISSIPPI A B MICHIGAN A A  
INDIANA A N OHIO A N KENTUCKY A B  
TENNESSEE A B ALABAMA A B NEW YORK N N  
VERMONT N N NEW HAMP N N MAINE N N  
MASS N B CONN N B RHODE IS N B  
PENN A B NEW JERSEY N B W VIRGINIA A B  
MARYLAND N B DELAWARE N B VIRGINIA N B  
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 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  
 
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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