808  
FXUS06 KWBC 222001  
PMDMRD  
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS  
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD  
300 PM EST MON JANUARY 22 2018  
 
6-10 DAY OUTLOOK FOR JAN 28 - FEB 01, 2018  
 
TODAY'S ENSEMBLE MEAN SOLUTIONS ARE IN FAIRLY GOOD AGREEMENT ON THE EXPECTED  
500-HPA FLOW PATTERN OVER THE FORECAST DOMAIN. A LOW AMPLITUDE FLOW PATTERN IS  
ANTICIPATED ACROSS MUCH OF THE CONUS WITH A WEAK TROUGH FORECAST OVER THE  
EAST-CENTRAL PART OF THE NATION AND A WEAK RIDGE ANTICIPATED OVER THE NORTHWEST.  
A RIDGE IS PREDICTED OVER THE CARIBBEAN, WHILE TROUGHS ARE EXPECTED NORTHEAST  
OF HUDSON BAY AND OVER MOST OF CENTRAL AND EASTERN MAINLAND ALASKA. THE  
ENSEMBLE SPAGHETTI CHARTS DEPICT MODERATE SPREAD OVER MOST OF THE FORECAST  
DOMAIN. THE AO INDEX WHICH RECENTLY HAS BEEN NEGATIVE IS FORECAST TO BE NEAR  
ZERO AT DAY 7, WEAKLY NEGATIVE AT 10 DAY, AND REMAIN WEAKLY NEGATIVE AT DAY 14.  
THE PNA INDEX WHICH RECENTLY HAS BEEN NEGATIVE IS FORECAST TO BE NEAR ZERO AT  
DAY 7, AND REMAIN CLOSE TO ZERO THROUGH DAY 14. TODAY'S 500-HPA BLEND CHART  
DEPICTS NEAR TO BELOW NORMAL HEIGHTS OVER THE NORTHWEST CONUS, THE ALASKA  
PANHANDLE, AND SOUTHEASTERN MAINLAND ALASKA, WHILE NEAR TO ABOVE NORMAL HEIGHTS  
ARE ANTICIPATED OVER THE REMAINDER OF THE FORECAST DOMAIN.  
 
ABOVE NORMAL HEIGHTS AND/OR ANOMALOUS WESTERLY FLOW ENHANCE PROBABILITIES OF  
NEAR TO ABOVE NORMAL TEMPERATURES FOR MOST OF THE CONUS. THE EXCEPTION IS OVER  
SOUTHERN TEXAS AND SOUTHERN LOUISIANA WHERE A WEAK TROUGH TILTS THE ODDS TO  
NEAR TO BELOW NORMAL TEMPERATURES. ANOMALOUS NORTHERLY FLOW ENHANCES  
PROBABILITIES OF BELOW NORMAL TEMPERATURES FOR MUCH OF ALASKA.  
 
THE TROUGH FORECAST OVER THE EAST-CENTRAL CONUS FAVORS ABOVE NORMAL  
PRECIPITATION FOR THE EASTERN QUARTER OF THE NATION. BELOW NORMAL HEIGHTS  
AND/OR ANOMALOUS WESTERLY FLOW ENHANCES PROBABILITIES OF ABOVE NORMAL  
PRECIPITATION FOR PARTS OF THE PACIFIC NORTHWEST, THE NORTHERN INTERMOUNTAIN  
WEST, NORTHERN ROCKIES, AND NORTHERN PLAINS. ABOVE NORMAL HEIGHTS AND/OR  
ANOMALOUS NORTHEASTERLY FLOW TILT THE ODDS TO NEAR TO BELOW NORMAL  
PRECIPITATION FOR THE REMAINDER OF THE CONUS AND ALASKA.  
 
THE OFFICIAL 6-10 DAY 500-HPA HEIGHT BLEND CONSISTS OF 15% OF TODAY'S 0Z GFS  
ENSEMBLE MEAN CENTERED ON DAY 8, 25% OF TODAY'S 6Z GFS ENSEMBLE MEAN CENTERED  
ON DAY 8, 30% OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 8, 10% 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: AVERAGE, 3 OUT OF 5, DUE TO FAIRLY  
GOOD AGREEMENT AMONG THE ENSEMBLE MEAN SOLUTIONS AND FAIR AGREEMENT AMONG THE  
SURFACE TOOLS.  
 
8-14 DAY OUTLOOK FOR JAN 30 - FEB 05, 2018  
 
THE OVERALL CIRCULATION PATTERN IS EXPECTED TO BE SOMEWHAT PROGRESSIVE DURING  
WEEK-2 AS HEIGHTS FALL OVER THE WEST-CENTRAL CONUS AND RISE OVER THE PACIFIC  
NORTHWEST. TROUGHING IS FORECAST TO DEVELOP OVER THE INTERIOR SOUTHWEST U.S.  
THE ENSEMBLE SPAGHETTI CHARTS INDICATE MODERATE SPREAD OVER THE EASTERN CONUS,  
AND MODERATE TO LARGE SPREAD OVER THE WESTERN CONUS AND EASTERN PACIFIC.  
TODAY'S 500-HPA BLENDED HEIGHT CHART DEPICTS NEAR TO BELOW NORMAL HEIGHTS OVER  
PARTS OF THE GREAT BASIN, THE ROCKIES, THE HIGH PLAINS, AND THE UPPER  
MISSISSIPPI VALLEY, WHILE NEAR TO ABOVE NORMAL HEIGHTS ARE ANTICIPATED OVER THE  
REMAINDER OF THE CONUS AND ALASKA.  
 
NEAR TO ABOVE NORMAL HEIGHTS ENHANCE PROBABILITIES OF ABOVE NORMAL TEMPERATURES  
FOR THE EASTERN CONUS, PARTS OF CALIFORNIA, THE SOUTHWEST, THE CENTRAL AND  
SOUTHERN PLAINS, AND THE ALEUTIANS. THE TROUGH OVER THE WEST-CENTRAL CONUS  
TILTS THE ODDS TO BELOW NORMAL TEMPERATURES FOR PARTS OF SOUTHERN TEXAS AND THE  
NORTHWESTERN AND NORTH-CENTRAL CONUS. ANOMALOUS NORTHERLY FLOW FAVORS BELOW  
NORMAL TEMPERATURES FOR EASTERN MAINLAND ALASKA.  
 
THE TROUGH OVER THE WEST-CENTRAL U.S. ENHANCES PROBABILITIES OF ABOVE NORMAL  
PRECIPITATION FOR MUCH OF THE CENTRAL AND EASTERN CONUS AS WELL AS PORTIONS OF  
THE NORTHERN ROCKIES AND NORTHERN PLAINS. ANOMALOUS NORTH/NORTHWESTERLY FLOW  
FAVORS BELOW NORMAL PRECIPITATION FOR PARTS OF THE SOUTHWESTERN CONUS.  
ANOMALOUS NORTHERLY FLOW TILTS THE ODDS TO BELOW NORMAL PRECIPITATION FOR  
NORTHERN ALASKA, WHILE ANOMALOUS SOUTHERLY FLOW ENHANCES PROBABILITIES FOR  
ABOVE NORMAL PRECIPITATION FOR THE ALEUTIANS AND PARTS OF SOUTHWESTERN MAINLAND  
ALASKA.  
 
THE OFFICIAL 8-14 DAY 500-HPA HEIGHT BLEND CONSISTS OF: 10% OF TODAY'S 0Z GFS  
ENSEMBLE MEAN CENTERED ON DAY 11, 15% OF TODAY'S 6Z GFS ENSEMBLE MEAN CENTERED  
ON DAY 11, 10% OF TODAY'S GFS SUPERENSEMBLE MEAN CENTERED ON DAY 11, 30% OF  
TODAY'S 0Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 11, 15% OF YESTERDAY'S 12Z  
EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 10, 10% OF TODAY'S 0Z CANADIAN ENSEMBLE  
MEAN CENTERED ON DAY 11, AND 10% OF YESTERDAY'S 12Z CANADIAN ENSEMBLE MEAN  
CENTERED ON DAY 10  
 
FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD: BELOW AVERAGE, 2 OUT OF 5, DUE TO  
RELATIVELY HIGH MODEL SPREAD.  
 
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  
FEBRUARY 15.  
 
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:  
19990128 - 19540126 - 19510121 - 19560103 - 20000111  
 
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:  
19990128 - 19660102 - 19510120 - 20080107 - 19680112  
 
6-10 DAY OUTLOOK TABLE  
OUTLOOK FOR JAN 28 - FEB 01, 2018  
 
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN  
WASHINGTON N A OREGON N N NRN CALIF A B  
SRN CALIF A B IDAHO A N NEVADA A B  
W MONTANA N A E MONTANA N A WYOMING N N  
UTAH A B ARIZONA A B COLORADO A B  
NEW MEXICO A B N DAKOTA N A S DAKOTA N N  
NEBRASKA N B KANSAS A B OKLAHOMA A B  
N TEXAS N B S TEXAS B B W TEXAS N B  
MINNESOTA N N IOWA A B MISSOURI A B  
ARKANSAS A N LOUISIANA N N WISCONSIN A B  
ILLINOIS A N MISSISSIPPI N N MICHIGAN A N  
INDIANA A A OHIO A A KENTUCKY A A  
TENNESSEE A A ALABAMA N 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 A GEORGIA A A  
FL PNHDL N A FL PENIN A A AK N SLOPE B B  
AK ALEUTIAN B B AK WESTERN B B AK INT BSN B B  
AK S INT B B AK SO COAST B B AK PNHDL B B  
 
 
 
8-14 DAY OUTLOOK TABLE  
OUTLOOK FOR JAN 30 - FEB 05, 2018  
 
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN  
WASHINGTON B N OREGON B B NRN CALIF N B  
SRN CALIF A B IDAHO B A NEVADA N B  
W MONTANA B A E MONTANA B A WYOMING B A  
UTAH N N ARIZONA A B COLORADO N A  
NEW MEXICO A B N DAKOTA B A S DAKOTA B A  
NEBRASKA N A KANSAS A A OKLAHOMA A A  
N TEXAS A N S TEXAS N B W TEXAS A B  
MINNESOTA N A IOWA N A MISSOURI A A  
ARKANSAS A A LOUISIANA A A WISCONSIN N 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 A GEORGIA A A  
FL PNHDL A A FL PENIN A N AK N SLOPE B B  
AK ALEUTIAN A A AK WESTERN N N AK INT BSN B B  
AK S INT N N AK SO COAST N N AK PNHDL B N  
 
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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