060  
FXUS06 KWBC 242002  
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 24 2018  
 
6-10 DAY OUTLOOK FOR JAN 30 - FEB 03, 2018  
 
TODAY'S ENSEMBLE MEAN SOLUTIONS ARE IN FAIRLY GOOD AGREEMENT ON THE EXPECTED  
500-HPA FLOW PATTERN OVER THE FORECAST DOMAIN. A MODERATE AMPLITUDE BROADLY  
CYCLONIC FLOW PATTERN IS ANTICIPATED ACROSS MUCH OF THE CONUS. RIDGES ARE  
PREDICTED OVER THE THE EAST PACIFIC AND CARIBBEAN, WHILE TROUGHS ARE EXPECTED  
NORTHEAST OF HUDSON BAY AND OVER MOST OF SOUTHERN AND EASTERN MAINLAND ALASKA.  
A STRONG CLOSED-OFF RIDGE IS FORECAST NORTHWEST OF ALASKA. THE ENSEMBLE  
SPAGHETTI CHARTS DEPICT LOW TO 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 NEGATIVE AT DAY 14. THE  
PNA INDEX WHICH RECENTLY HAS BEEN WEAKLY NEGATIVE IS FORECAST TO BE NEAR ZERO  
AT DAY 7, REMAIN CLOSE TO ZERO AT DAY 10, AND BE WEAKLY POSITIVE BY DAY 14.  
TODAY'S 500-HPA BLEND CHART DEPICTS NEAR TO BELOW NORMAL HEIGHTS OVER THE  
NORTHWEST AND NORTH-CENTRAL CONUS AND THE ALASKA PANHANDLE, WHILE NEAR TO ABOVE  
NORMAL HEIGHTS ARE ANTICIPATED OVER THE REMAINDER OF THE FORECAST DOMAIN.  
 
ABOVE NORMAL HEIGHTS ENHANCE PROBABILITIES OF NEAR TO ABOVE NORMAL TEMPERATURES  
FOR MOST OF THE CONUS, BUT BELOW NORMAL TEMPERATURES ARE EXPECTED TO EXPAND  
SOUTHEAST ACROSS THE CENTRAL CONUS LATE IN THE PERIOD. THE EXCEPTION IS OVER  
PARTS OF THE NORTHWESTERN AND NORTH-CENTRAL CONUS WHERE BELOW NORMAL HEIGHTS  
TILT THE ODDS TO NEAR TO BELOW NORMAL TEMPERATURES. ANOMALOUS  
NORTH/NORTHEASTERLY FLOW ENHANCES PROBABILITIES OF BELOW NORMAL TEMPERATURES  
FOR SOUTHEASTERN MAINLAND ALASKA AND THE ALASKA PANHANDLE, WHILE ABOVE NORMAL  
HEIGHTS TILT THE ODDS TO ABOVE NORMAL TEMPERATURES FOR THE ALEUTIANS.  
 
THE BROAD TROUGH FORECAST OVER THE CONUS FAVORS ABOVE NORMAL PRECIPITATION FOR  
THE EASTERN THIRD OF THE NATION. BELOW NORMAL HEIGHTS AND/OR ANOMALOUS WESTERLY  
FLOW ENHANCES PROBABILITIES OF ABOVE NORMAL PRECIPITATION FOR PARTS OF THE  
NORTHERN INTERMOUNTAIN WEST, NORTHERN AND CENTRAL ROCKIES, AND NORTHERN PLAINS.  
ABOVE NORMAL HEIGHTS AND/OR ANOMALOUS NORTHWESTERLY 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 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 0Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 8, 30% OF  
YESTERDAY'S 12Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 7, AND 10% OF  
YESTERDAY'S OPERATIONAL 12Z ECMWF 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 FEB 01 - 07 2018  
 
ENSEMBLE MEAN SOLUTIONS GENERALLY INDICATE THE OVERALL CIRCULATION PATTERN WILL  
BE SOMEWHAT PROGRESSIVE AND AMPLIFY DURING WEEK-2 AS HEIGHTS FALL OVER THE  
CENTRAL CONUS AND RISE OVER THE PACIFIC NORTHWEST. THE EXCEPTION IS THE  
CANADIAN ENSEMBLE MEAN SOLUTION WHICH SHOWS LITTLE CHANGE FROM ITS FORECAST FOR  
THE 6-10 DAY PERIOD. THE ENSEMBLE SPAGHETTI CHARTS INDICATE LOW TO 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 THE NORTH-CENTRAL CONUS, WHILE NEAR TO ABOVE NORMAL  
HEIGHTS ARE ANTICIPATED OVER THE REMAINDER OF THE CONUS AND ALASKA.  
 
FOR THE CONUS, AREAS THAT ARE EXPECTED TO HAVE NEAR TO ABOVE (BELOW) NORMAL  
HEIGHTS GENERALLY CORRESPOND TO AREAS THAT ARE FORECAST TO HAVE ENHANCED  
PROBABILITIES FOR ABOVE (BELOW) NORMAL TEMPERATURES. THE EXCEPTION IS FOR THE  
NORTHWEST CONUS WHERE ANOMALOUS NORTHERLY FLOW FAVORS BELOW NORMAL  
TEMPERATURES. ANOMALOUS NORTHERLY FLOW TILTS THE ODDS TO BELOW NORMAL  
TEMPERATURES FOR PARTS OF SOUTHEASTERN MAINLAND ALASKA AND THE ALASKA  
PANHANDLE. ABOVE NORMAL HEIGHTS FAVOR ABOVE NORMAL TEMPERATURES FOR THE  
ALEUTIANS AND PARTS OF WESTERN MAINLAND ALASKA.  
 
THE TROUGH OVER THE 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 AND CENTRAL PLAINS. ABOVE NORMAL HEIGHTS  
AND/OR ANOMALOUS NORTH/NORTHWESTERLY FLOW FAVORS BELOW NORMAL PRECIPITATION FOR  
PARTS OF THE WESTERN AND SOUTH-CENTRAL CONUS. ANOMALOUS NORTHERLY FLOW AND/OR  
ABOVE NORMAL HEIGHTS TILT THE ODDS TO BELOW NORMAL PRECIPITATION FOR MAINLAND  
ALASKA AND THE ALASKA PANHANDLE, WHILE ANOMALOUS SOUTHEASTERLY FLOW ENHANCES  
PROBABILITIES FOR ABOVE NORMAL PRECIPITATION FOR THE ALEUTIANS.  
 
THE OFFICIAL 8-14 DAY 500-HPA HEIGHT BLEND CONSISTS OF: 15% OF TODAY'S 0Z GFS  
ENSEMBLE MEAN CENTERED ON DAY 11, 15% OF TODAY'S 6Z GFS ENSEMBLE MEAN CENTERED  
ON DAY 11, 20% OF TODAY'S GFS SUPERENSEMBLE MEAN CENTERED ON DAY 11, 30% OF  
TODAY'S 0Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 11, AND 20% OF YESTERDAY'S  
12Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 10  
 
FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD: ABOUT AVERAGE, 3 OUT OF 5, DUE TO  
FAIR AGREEMENT AMONG THE ENSEMBLE MODEL SOLUTIONS AND MODERATE TO HIGH SPREAD  
AMONG ENSEMBLE MEMBERS OVER PARTS OF THE FORECAST DOMAIN.  
 
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 - 19510121 - 20000111 - 19540126 - 19680113  
 
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:  
19680112 - 19510121 - 19560107 - 19990131 - 19590113  
 
6-10 DAY OUTLOOK TABLE  
OUTLOOK FOR JAN 30 - FEB 03, 2018  
 
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN  
WASHINGTON B N OREGON N N NRN CALIF A B  
SRN CALIF A B IDAHO N N NEVADA A B  
W MONTANA B A E MONTANA B A WYOMING N A  
UTAH A N ARIZONA A B COLORADO A N  
NEW MEXICO A B N DAKOTA B A S DAKOTA B N  
NEBRASKA N N KANSAS A N OKLAHOMA A N  
N TEXAS N B S TEXAS N B W TEXAS A B  
MINNESOTA B A IOWA N N MISSOURI A A  
ARKANSAS N A LOUISIANA N N WISCONSIN N A  
ILLINOIS A A MISSISSIPPI N A MICHIGAN A A  
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 A A FL PENIN A A AK N SLOPE N B  
AK ALEUTIAN A N AK WESTERN N 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 FEB 01 - 07 2018  
 
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN  
WASHINGTON B N OREGON N B NRN CALIF A B  
SRN CALIF A B IDAHO N N NEVADA A B  
W MONTANA B A E MONTANA B A WYOMING B N  
UTAH A B ARIZONA A B COLORADO N B  
NEW MEXICO A B N DAKOTA B A S DAKOTA B A  
NEBRASKA B A KANSAS B N OKLAHOMA B B  
N TEXAS B B S TEXAS N B W TEXAS N B  
MINNESOTA B A IOWA B A MISSOURI B A  
ARKANSAS B A LOUISIANA N A WISCONSIN B A  
ILLINOIS B A MISSISSIPPI N A MICHIGAN B A  
INDIANA B A OHIO N A KENTUCKY N 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 A AK N SLOPE N B  
AK ALEUTIAN A N AK WESTERN A 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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