697  
FXUS06 KWBC 092028  
PMDMRD  
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS  
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD  
300 PM EST TUE JANUARY 09 2018  
 
6-10 DAY OUTLOOK FOR JAN 15 - 19 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 RIDGE IS PREDICTED OVER WESTERN NORTH AMERICA. DOWNSTREAM, A  
TROUGH IS FORECAST OVER THE EASTERN CONUS. 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 WESTERN 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  
LIKELY FOR THE EASTERN CONUS, UNDERNEATH THE PREDICTED TROUGH.  
 
EAST OF THE UPPER-LEVEL TROUGH PREDICTED OVER THE ALEUTIANS, SOUTHEASTERLY FLOW  
AT THE SURFACE INCREASES CHANCES OF ABOVE NORMAL PRECIPITATION OVER SOUTHERN  
ALASKA, THE ALEUTIANS. ABOVE NORMAL PRECIPITATION IS ALSO FAVORED FOR THE  
NORTHWESTERN CONUS, THE UPPER MIDDLE MISSISSIPPI VALLEY AND PORTIONS OF THE  
GREAT LAKES REGION, DUE TO PREDICTED FRONTAL ACTIVITY AND SOUTHWESTERLY SURFACE  
FLOW. PROBABILITIES OF BELOW NORMAL PRECIPITATION ACROSS THE SOUTHWESTERN  
CONUS, THE GULF COAST REGION, AND THE ATLANTIC COAST STATES ARE SUPPORTED BY  
THE ANOMALOUS RIDGE FORECAST IN THE WESTERN CONUS AND THE NORTHEASTERLY SURFACE  
FLOW OVER THE SOUTHEASTERN CONUS. 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 17 - 23 2018  
 
DURING WEEK-2, MODELS ARE IN FAIRLY GOOD AGREEMENT, AND THEY PREDICT A SIMILAR  
CIRCULATION PATTERN TO THAT EXPECTED DURING THE 6-10 DAY PERIOD. THE TROUGH  
PREDICTED OVER THE EAST-CENTRAL CONUS IS FORECAST TO DEAMPLIFY 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 STILL FAVORED FOR MOST OF MAINLAND 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.  
 
FOR THE WEEK-2 PRECIPITATION OUTLOOK, BELOW NORMAL PRECIPITATION IS PREDICTED  
OVER SOUTHERN ALASKA AND THE ALASKA PANHANDLE AS THE ANOMALOUS TROUGH  
PROGRESSES TO THE WESTERN COAST. TROUGHING OVER THE WEST COAST AND EASTERN  
CONUS SUPPORTS STORM ACTIVITY FROM THE WESTERN CONUS TO THE GREAT LAKES, 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, THE EAST GULF COAST REGION, AND THE SOUTH 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:  
19570101 - 20010123 - 19851229 - 19900111 - 20090121  
 
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:  
19570101 - 19851229 - 19890102 - 20010122 - 20090121  
 
6-10 DAY OUTLOOK TABLE  
OUTLOOK FOR JAN 15 - 19 2018  
 
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN  
WASHINGTON A A OREGON A A NRN CALIF A A  
SRN CALIF A N 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 A S DAKOTA N A  
NEBRASKA N A KANSAS N N OKLAHOMA N N  
N TEXAS A N S TEXAS A N W TEXAS A B  
MINNESOTA B A IOWA B A MISSOURI B A  
ARKANSAS B A LOUISIANA B B WISCONSIN B A  
ILLINOIS B A MISSISSIPPI B B MICHIGAN B A  
INDIANA B A OHIO B N KENTUCKY B B  
TENNESSEE B B ALABAMA B B NEW YORK B B  
VERMONT B B NEW HAMP B B MAINE N B  
MASS B B CONN B B RHODE IS B B  
PENN B B 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 A AK WESTERN A N AK INT BSN A A  
AK S INT A A AK SO COAST A A AK PNHDL A N  
 
 
 
8-14 DAY OUTLOOK TABLE  
OUTLOOK FOR JAN 17 - 23 2018  
 
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN  
WASHINGTON N A OREGON N A NRN CALIF N A  
SRN CALIF A A IDAHO A A NEVADA A A  
W MONTANA N A E MONTANA B A WYOMING A A  
UTAH A A ARIZONA A N COLORADO A A  
NEW MEXICO A B N DAKOTA B A S DAKOTA A A  
NEBRASKA A A KANSAS A A OKLAHOMA A A  
N TEXAS A A S TEXAS A N 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 B 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 B 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 N AK INT BSN A B  
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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