857  
FXUS06 KWBC 112007  
PMDMRD  
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS  
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD  
300 PM EST THU JANUARY 11 2018  
 
6-10 DAY OUTLOOK FOR JAN 17 - 21 2018  
 
TODAY'S ENSEMBLE MEAN SOLUTIONS ARE IN GOOD AGREEMENT ON THE PREDICTED 500-HPA  
FLOW PATTERN OVER THE FORECAST DOMAIN. AN AMPLIFIED TROUGH IS EXPECTED OVER THE  
GULF OF ALASKA. A TROUGH IS FORECAST TO EXIT THE EASTERN CONUS DURING THE  
PERIOD. ABOVE NORMAL 500-HPA HEIGHTS ARE PREDICTED OVER THE CENTRAL AND EASTERN  
CONUS, WHILE BELOW NORMAL 500-HPA HEIGHTS ARE FORECAST FOR MUCH OF THE WESTERN  
CONUS.  
 
ABOVE NORMAL HEIGHTS FORECAST OVER THE SOUTHWESTERN CONUS AND NORTHERN ALASKA,  
AND RIDGING OVER NORTHWESTERN NORTH AMERICA, LEADS TO INCREASED CHANCES OF  
ABOVE NORMAL TEMPERATURES FOR MUCH OF THE WESTERN AND CENTRAL CONUS AS WELL AS  
NORTHERN ALASKA. BELOW NORMAL TEMPERATURES ARE FAVORED FOR PARTS OF THE  
SOUTHEASTERN CONUS, BEHIND A TROUGH MOVING OUT EARLY IN THE PERIOD.  
 
OFFSHORE FLOW AT THE SURFACE INCREASES CHANCES OF BELOW NORMAL PRECIPITATION  
OVER SOUTHERN ALASKA, WHILE ABOVE NORMAL PRECIPITATION IS FORECAST OVER  
NORTHERN ALASKA. ABOVE NORMAL PRECIPITATION IS ALSO FAVORED FOR THE WESTERN  
CONUS, THE MISSISSIPPI VALLEY, AND THE GREAT LAKES REGION, DUE TO PREDICTED  
FRONTAL ACTIVITY AND SOUTHWESTERLY SURFACE FLOW. ENHANCED PROBABILITIES OF  
BELOW NORMAL PRECIPITATION ACROSS THE SOUTHERN HIGH PLAINS, THE EAST GULF COAST  
REGION, AND THE MIDDLE AND SOUTHERN ATLANTIC COAST STATES ARE CONSISTENT WITH  
PREDICTIONS FROM THE ECMWF AND GEFS CALIBRATED REFORECAST TOOLS.  
 
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  
REASONABLY GOOD AGREEMENT AMONG MOST MODELS AND TOOLS.  
 
8-14 DAY OUTLOOK FOR JAN 19 - 25 2018  
 
DURING WEEK-2, MODELS ARE IN FAIRLY GOOD AGREEMENT, AND THEY PREDICT THAT THE  
TROUGH OVER THE EAST PACIFIC IS LIKELY TO MOVE CLOSER TO THE WEST COAST. THE  
TROUGH PREDICTED OVER THE EASTERN CONUS IS FORECAST TO MOVE OFFSHORE OF THE  
EAST COAST DURING WEEK-2, WITH RAPIDLY RISING MID-TROPOSPHERIC HEIGHTS AND  
POSITIVE ANOMALOUS HEIGHTS OVER THIS REGION, WHILE NEGATIVE ANOMALOUS HEIGHTS  
MOVE INTO THE WESTERN CONUS.  
 
WARMER THAN NORMAL CONDITIONS ARE ANTICIPATED TO SPREAD RAPIDLY EASTWARD ACROSS  
MOST OF THE CENTRAL AND EASTERN CONUS DURING THE WEEK-2 PERIOD, ASSOCIATED WITH  
POSITIVE ANOMALOUS HEIGHTS. BELOW NORMAL TEMPERATURES ARE FAVORED FOR THE  
WESTERN CONUS, SOUTHERN ALASKA, AND THE ALASKA PANHANDLE, DUE TO THE NEGATIVE  
ANOMALOUS HEIGHTS FORECAST OVER THE WESTERN CONUS.  
 
FOR THE WEEK-2 PRECIPITATION OUTLOOK, BELOW NORMAL PRECIPITATION IS FAVORED  
OVER ALASKA, AS THE ANOMALOUS TROUGH PROGRESSES TO THE WESTERN COAST OF NORTH  
AMERICA. TROUGHING OVER THE WEST COAST AND ENHANCED PACIFIC FLOW SUPPORT STORM  
ACTIVITY FROM THE WESTERN CONUS TO THE GREAT LAKES, THE MISSISSIPPI VALLEY, THE  
OHIO AND THE TENNESSEE VALLEYS AND NORTHEAST, WHERE NEAR TO ABOVE NORMAL  
PRECIPITATION IS FAVORED. BELOW NORMAL PRECIPITATION IS LIKELY FOR PARTS OF THE  
SOUTHERN PLAINS, AND THE SOUTHERN ATLANTIC COAST STATES, CONSISTENT WITH  
PREDICTION FROM THE ECMWF AND GEFS REFORECAST TOOLS.  
 
THE OFFICIAL 8-14 DAY 500-HPA HEIGHT BLEND CONSISTS OF: 20% 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, 20% OF  
TODAY'S 0Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 11, AND 20% OF TODAY'S 0Z  
CANADIAN ENSEMBLE MEAN CENTERED ON DAY 11  
 
FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD: NEAR AVERAGE, 3 OUT OF 5, DUE TO  
REASONABLE OVERALL MODEL AND TOOL AGREEMENT, BUT OFFSET BY THE UNCERTAINTY  
INHERENT IN A TRANSITIONING CIRCULATION PATTERN.  
 
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  
JANUARY 18.  
 
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:  
19530115 - 20060109 - 19900117 - 19841229 - 19900103  
 
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:  
19530116 - 19670120 - 19660109 - 19900120 - 19650122  
 
6-10 DAY OUTLOOK TABLE  
OUTLOOK FOR JAN 17 - 21 2018  
 
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN  
WASHINGTON A A OREGON N A NRN CALIF N A  
SRN CALIF A A IDAHO A A NEVADA A A  
W MONTANA A A E MONTANA A A WYOMING A A  
UTAH A A ARIZONA A A 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 A S TEXAS A A W TEXAS A B  
MINNESOTA A A IOWA A A MISSOURI N A  
ARKANSAS N A LOUISIANA B N WISCONSIN A A  
ILLINOIS N A MISSISSIPPI B N MICHIGAN A A  
INDIANA N A OHIO N A KENTUCKY B A  
TENNESSEE B A ALABAMA B B NEW YORK N A  
VERMONT A A NEW HAMP A A MAINE A A  
MASS N A CONN N N RHODE IS N N  
PENN N N NEW JERSEY N B W VIRGINIA B N  
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 A B AK INT BSN A N  
AK S INT N B AK SO COAST N B AK PNHDL N B  
 
 
 
8-14 DAY OUTLOOK TABLE  
OUTLOOK FOR JAN 19 - 25 2018  
 
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN  
WASHINGTON B A OREGON B A NRN CALIF B A  
SRN CALIF B A IDAHO B A NEVADA B A  
W MONTANA B A E MONTANA N A WYOMING N A  
UTAH N A ARIZONA N A COLORADO A A  
NEW MEXICO A A N DAKOTA A A S DAKOTA A A  
NEBRASKA A A KANSAS A A OKLAHOMA A A  
N TEXAS A A S TEXAS A B W TEXAS A B  
MINNESOTA A A IOWA A A MISSOURI A A  
ARKANSAS A A LOUISIANA A A WISCONSIN A A  
ILLINOIS A A MISSISSIPPI A A MICHIGAN A A  
INDIANA A A OHIO A A KENTUCKY A A  
TENNESSEE A A ALABAMA A A NEW YORK A A  
VERMONT A A NEW HAMP A A MAINE A A  
MASS A A CONN A A RHODE IS A N  
PENN A A NEW JERSEY A A W VIRGINIA A A  
MARYLAND A A DELAWARE A N 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 N B  
AK ALEUTIAN N B AK WESTERN N B AK INT BSN N B  
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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