178  
FXUS06 KWBC 102001  
PMDMRD  
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS  
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD  
300 PM EST WED JANUARY 10 2018  
 
6-10 DAY OUTLOOK FOR JAN 16 - 20 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. AN AMPLIFIED TROUGH IS FORECAST TO EXIT THE EASTERN CONUS  
DURING THE PERIOD. ABOVE NORMAL 500-HPA HEIGHTS ARE PREDICTED OVER ALASKA AND  
THE CENTRAL AND EASTERN CONUS, WHILE BELOW NORMAL 500-HPA HEIGHTS ARE FORECAST  
FOR THE NORTHWEST.  
 
ABOVE NORMAL HEIGHTS FORECAST OVER THE SOUTHWESTERN CONUS AND ALASKA, WITH  
SOUTHWESTERLY SURFACE FLOW OVER THE NORTHWEST CONUS, LEADS TO INCREASED CHANCES  
OF ABOVE NORMAL TEMPERATURES IN THESE AREAS. BELOW NORMAL TEMPERATURES ARE  
FAVORED FOR PARTS OF THE CENTRAL AND SOUTHEASTERN CONUS, DUE TO LARGE NEGATIVE  
ANOMALOUS EARLY IN THE PERIOD.  
 
WEST OF THE UPPER-LEVEL TROUGH PREDICTED OVER THE GULF OF ALASAKA, OFFSHORE  
FLOW AT THE SURFACE INCREASES CHANCES OF BELOW NORMAL PRECIPITATION OVER  
SOUTHERN ALASKA, THE ALEUTIANS, AND THE ALASKA PANHANDLE, WHILE ABOVE NORMAL  
PRECIPITATION IS FORECAST OVER NORTHERN ALASKA. ABOVE NORMAL PRECIPITATION IS  
ALSO FAVORED FOR THE WESTERN CONUS, THE MIDDLE AND LOWER MISSISSIPPI VALLEY,  
DUE TO PREDICTED FRONTAL ACTIVITY AND SOUTHWESTERLY SURFACE FLOW. PROBABILITIES  
OF BELOW NORMAL PRECIPITATION ACROSS THE SOUTHERN PLAINS, THE EAST GULF COAST  
REGION, AND THE ATLANTIC COAST STATES ARE SUPPORTED BY THE SURFACE RIDGE  
FORECAST EARLY IN THE PERIOD. THAT PATTERN IS CONSISTENT WITH PREDICTION 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 18 - 24 2018  
 
DURING WEEK-2, MODELS ARE IN FAIRLY GOOD AGREEMENT, AND THEY PREDICT THAT  
TROUGH OVER THE EAST PACIFIC IS LIKELY TO MOVING CLOSER TO THE WEST COAST. THE  
TROUGH PREDICTED OVER THE EAST-CENTRAL 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.  
 
ABOVE NORMAL TEMPERATURES ARE FAVORED FOR WESTERN ALASKA AND THE ALEUTIANS.  
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  
THE POSITIVE ANOMALOUS HEIGHTS ACROSS THE CENTRAL AND EAST-CENTRAL CONUS. BELOW  
NORMAL TEMPERATURES ARE FAVORED FOR THE WEST COAST AND THE NORTHERN ROCKIES DUE  
TO THE NEGATIVE ANOMALOUS HEIGHTS FORECAST OVER THE WESTERN CONUS.  
 
FOR THE WEEK-2 PRECIPITATION OUTLOOK, BELOW NORMAL PRECIPITATION IS FORECAST  
OVER SOUTHERN ALASKA, THE ALEUTIANS, AND THE ALASKA PANHANDLE AS THE ANOMALOUS  
TROUGH PROGRESSES TO THE WESTERN COAST. TROUGHING OVER THE WEST COAST AND  
INHANCED 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 SOME OF THE SOUTHERN PLAINS, PORTIONS OF THE EAST  
GULF COAST, 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:  
20010123 - 20070118 - 20060108 - 19660110 - 19870114  
 
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:  
19660110 - 20010123 - 19711226 - 19610110 - 19530114  
 
6-10 DAY OUTLOOK TABLE  
OUTLOOK FOR JAN 16 - 20 2018  
 
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN  
WASHINGTON A A OREGON A A NRN CALIF A A  
SRN CALIF A A IDAHO A A NEVADA A A  
W MONTANA A A E MONTANA N A WYOMING A A  
UTAH A A ARIZONA A B COLORADO A A  
NEW MEXICO A B N DAKOTA N N S DAKOTA N A  
NEBRASKA N A KANSAS N N OKLAHOMA N A  
N TEXAS N N S TEXAS A N W TEXAS A B  
MINNESOTA N N IOWA B A MISSOURI B A  
ARKANSAS B A LOUISIANA N B WISCONSIN N N  
ILLINOIS B A MISSISSIPPI B B MICHIGAN N N  
INDIANA B A OHIO B N KENTUCKY B A  
TENNESSEE B B ALABAMA B B NEW YORK B N  
VERMONT A B NEW HAMP A B MAINE A B  
MASS N B CONN N B RHODE IS N B  
PENN B N 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 N AK WESTERN A N AK INT BSN A N  
AK S INT A B AK SO COAST A B AK PNHDL A B  
 
 
 
8-14 DAY OUTLOOK TABLE  
OUTLOOK FOR JAN 18 - 24 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 N A NEVADA N A  
W MONTANA B A E MONTANA N A WYOMING N 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 B W TEXAS A B  
MINNESOTA A A IOWA A A MISSOURI A A  
ARKANSAS A A LOUISIANA A N 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 A  
PENN A A NEW JERSEY A A W VIRGINIA A A  
MARYLAND A A DELAWARE A A VIRGINIA A A  
N CAROLINA A A S CAROLINA A B GEORGIA A B  
FL PNHDL A B FL PENIN A B AK N SLOPE A N  
AK ALEUTIAN A N AK WESTERN A B AK INT BSN N 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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