062  
FXUS06 KWBC 252001  
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 25 2018  
 
6-10 DAY OUTLOOK FOR JAN 31 - FEB 04, 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 EAST PACIFIC AND CARIBBEAN, WHILE A TROUGH IS EXPECTED NORTH  
OF HUDSON BAY. A STRONG CLOSED-OFF RIDGE IS FORECAST NORTHWEST OF ALASKA. A  
WEAK TROUGH IS FORECAST OVER SOUTHERN ALASKA BETWEEN THE RIDGE FORECAST OVER  
THE EAST PACIFIC AND THE CLOSED-OFF RIDGE EXPECTED NORTHWEST OF THE STATE. THE  
ENSEMBLE SPAGHETTI CHARTS DEPICT LOW TO MODERATE SPREAD OVER MOST OF THE  
FORECAST DOMAIN. THE AO INDEX WHICH RECENTLY HAS BEEN WEAKLY 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 NORTH-CENTRAL CONUS, 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 THE EXTREME EASTERN CONUS, MUCH OF THE SOUTHWEST U.S., AND EXTREME WESTERN  
MAINLAND ALASKA AND THE ALEUTIANS. NEAR TO BELOW NORMAL HEIGHTS TILT THE ODDS  
TO NEAR TO BELOW NORMAL TEMPERATURES FOR THE REMAINDER OF THE CONUS. ANOMALOUS  
NORTHERLY FLOW FAVORS BELOW NORMAL TEMPERATURES FOR SOUTHEASTERN MAINLAND  
ALASKA AND THE ALASKA PANHANDLE.  
 
THE BROAD TROUGH FORECAST OVER THE CONUS FAVORS ABOVE NORMAL PRECIPITATION FOR  
THE EASTERN THIRD OF THE NATION. THE EXPECTATION OF UPSLOPE FLOW ENHANCES  
PROBABILITIES OF ABOVE NORMAL PRECIPITATION FOR PARTS OF THE NORTHERN AND  
CENTRAL ROCKIES AND NORTHERN AND CENTRAL PLAINS. ANOMALOUS SOUTHEASTERLY FLOW  
TILT THE ODDS TO ABOVE NORMAL PRECIPITATION FOR THE ALEUTIANS. ABOVE NORMAL  
HEIGHTS AND/OR ANOMALOUS NORTHWESTERLY FLOW FAVORS 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, 25% OF TODAY'S 6Z GFS ENSEMBLE MEAN CENTERED  
ON DAY 8, 5% OF TODAY'S OPERATIONAL 6Z GFS CENTERED ON DAY 8, 30% OF TODAY'S 0Z  
EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 8, AND 20% OF YESTERDAY'S 12Z EUROPEAN  
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 FEB 02 - 08 2018  
 
ENSEMBLE MEAN SOLUTIONS GENERALLY INDICATE LITTLE CHANGE TO THE OVERALL  
CIRCULATION PATTERN DURING WEEK-2 FROM THAT 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 IS QUITE SIMILAR TO THAT FORECAST DURING  
THE 6-10 DAY PERIOD.  
 
ABOVE NORMAL HEIGHTS ENHANCE PROBABILITIES FOR ABOVE NORMAL TEMPERATURES FOR  
THE SOUTHEASTERN AND SOUTHWESTERN CONUS. BELOW NORMAL HEIGHTS AND/OR ANOMALOUS  
WESTERLY FLOW TILT THE ODDS TO NEAR TO BELOW NORMAL TEMPERATURES FOR MUCH OF  
THE CENTRAL CONUS AND PARTS OF THE PACIFIC NORTHWEST, NORTHERN INTERMOUNTAIN  
WEST, AND NORTHERN ROCKIES. ABOVE NORMAL HEIGHTS FAVOR ABOVE NORMAL TEMPERATURE  
FOR THE ALEUTIANS AND WESTERN AND CENTRAL MAINLAND ALASKA. ANOMALOUS NORTHERLY  
FLOW ENHANCES PROBABILITIES FOR BELOW NORMAL TEMPERATURES FOR EXTREME  
SOUTHEASTERN MAINLAND ALASKA AND THE ALASKA PANHANDLE.  
 
THE TROUGH OVER THE CENTRAL U.S. ENHANCES PROBABILITIES OF ABOVE NORMAL  
PRECIPITATION FOR MUCH OF THE EAST-CENTRAL AND EASTERN CONUS. UPSLOPE FLOW  
TILTS THE ODDS TO ABOVE NORMAL PRECIPITATION FOR 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 SOUTHWESTERN CONUS. ANOMALOUS NORTHERLY FLOW AND/OR ABOVE NORMAL  
HEIGHTS TILT THE ODDS TO BELOW NORMAL PRECIPITATION FOR CENTRAL AND EASTERN  
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, 15% 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, AND 10% OF TODAY'S 0Z CANADIAN  
ENSEMBLE MEAN CENTERED ON DAY 11  
 
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 - 20000111 - 19510120 - 19590107 - 19680114  
 
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:  
19590106 - 19560105 - 19680112 - 20000113 - 19510121  
 
6-10 DAY OUTLOOK TABLE  
OUTLOOK FOR JAN 31 - FEB 04, 2018  
 
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN  
WASHINGTON B B OREGON B B NRN CALIF A B  
SRN CALIF A B IDAHO B N NEVADA A B  
W MONTANA B A E MONTANA B A WYOMING B A  
UTAH A N ARIZONA A B COLORADO B A  
NEW MEXICO A B N DAKOTA B A S DAKOTA B A  
NEBRASKA B A KANSAS B N OKLAHOMA N N  
N TEXAS N N S TEXAS N N W TEXAS N B  
MINNESOTA B N IOWA B N MISSOURI N N  
ARKANSAS N A LOUISIANA N A WISCONSIN B N  
ILLINOIS N A MISSISSIPPI N A MICHIGAN N N  
INDIANA N A OHIO N A KENTUCKY N A  
TENNESSEE N A ALABAMA N A NEW YORK N A  
VERMONT N A NEW HAMP A A MAINE A A  
MASS A A CONN A A RHODE IS A A  
PENN N A NEW JERSEY A A W VIRGINIA N A  
MARYLAND A A DELAWARE A A VIRGINIA N A  
N CAROLINA A A S CAROLINA N A GEORGIA N A  
FL PNHDL N A FL PENIN N N AK N SLOPE N B  
AK ALEUTIAN A N AK WESTERN N B AK INT BSN N B  
AK S INT B B AK SO COAST B B AK PNHDL B B  
 
 
 
8-14 DAY OUTLOOK TABLE  
OUTLOOK FOR FEB 02 - 08 2018  
 
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN  
WASHINGTON B B 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 A  
UTAH A B ARIZONA A B COLORADO B B  
NEW MEXICO A B N DAKOTA B A S DAKOTA B A  
NEBRASKA B A KANSAS B N OKLAHOMA B N  
N TEXAS B N S TEXAS N A W TEXAS B B  
MINNESOTA B N IOWA B A MISSOURI B A  
ARKANSAS B A LOUISIANA N A WISCONSIN B N  
ILLINOIS B A MISSISSIPPI B A MICHIGAN B A  
INDIANA B A OHIO B A KENTUCKY B A  
TENNESSEE B A ALABAMA N A NEW YORK B A  
VERMONT N A NEW HAMP N A MAINE N A  
MASS N A CONN N A RHODE IS N A  
PENN B A NEW JERSEY N A W VIRGINIA B A  
MARYLAND N A DELAWARE N A VIRGINIA N A  
N CAROLINA N A S CAROLINA A A GEORGIA A A  
FL PNHDL A A FL PENIN A N AK N SLOPE A B  
AK ALEUTIAN A N AK WESTERN A N AK INT BSN A B  
AK S INT A 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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