505  
FXUS06 KWBC 282001  
PMDMRD  
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS  
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD  
300 PM EST WED FEBRUARY 28 2018  
 
6-10 DAY OUTLOOK FOR MAR 06 - 10 2018  
 
TODAY'S MODEL SOLUTIONS FEATURE STRONG POSITIVE 500-HPA ANOMALIES AT HIGH  
LATITUDES CONSISTENT WITH A NEGATIVE AO PATTERN. RIDGES ARE PREDICTED SOUTH OF  
THE ALEUTIANS AS WELL AS OVER EASTERN CANADA CENTERED OVER OR JUST TO THE NORTH  
OF NORTHERN QUEBEC. FARTHER TO THE SOUTH, NEAR TO BELOW NORMAL HEIGHTS ARE  
EXPECTED FOR MUCH OF THE CONUS AS A TROUGH OVER THE NORTH-CENTRAL CONUS EARLY  
IN THE PERIOD PROGRESSES TOWARD THE NORTHEASTERN CONUS LATER IN THE PERIOD.  
POSITIVE HEIGHT ANOMALIES ARE INDICATED FOR PARTS OF THE SOUTHWESTERN CONUS AS  
HEIGHTS RISE IN ADVANCE OF A TROUGH PREDICTED OVER THE EASTERN PACIFIC.  
POSITIVE HEIGHT ANOMALIES ARE ALSO EXPECTED FOR PARTS OF NORTHERN NEW ENGLAND  
IN ASSOCIATION WITH THE MEAN RIDGE OVER EASTERN CANADA. ENSEMBLE SPREAD IS LOW  
TO MODERATE TODAY OVER MUCH OF THE FORECAST DOMAIN. TODAY'S MANUAL 500-HPA  
HEIGHT BLEND IS BASED PRIMARILY ON THE ENSEMBLE MEAN SOLUTIONS.  
 
BELOW NORMAL HEIGHTS LEAD TO ENHANCED PROBABILITIES OF BELOW NORMAL  
TEMPERATURES ACROSS THE NORTHERN PLAINS AND THE NORTHWESTERN CONUS.  
TELECONNECTIONS ASSOCIATED WITH THE RIDGE OVER EASTERN CANADA FAVOR ABOVE  
NORMAL TEMPERATURES FOR PARTS OF THE GREAT LAKES AND NORTHEAST. THERE ARE  
ENHANCED PROBABILITIES OF BELOW NORMAL TEMPERATURES FOR THE SOUTHEASTERN CONUS  
DUE TO A TROUGH AND ASSOCIATED BELOW NORMAL HEIGHTS. RIDGING EARLY IN THE  
PERIOD AND ABOVE NORMAL SSTS LEAD TO FAVORED ABOVE NORMAL TEMPERATURES ACROSS  
MUCH OF THE ALEUTIANS AND PARTS OF WESTERN MAINLAND ALASKA. TROUGH DEVELOPMENT  
DOWNSTREAM FAVORS BELOW NORMAL TEMPERATURES FOR PARTS OF SOUTHEASTERN MAINLAND  
ALASKA AND THE PANHANDLE.  
 
MOIST FLOW AHEAD OF A TROUGH IN THE EASTERN PACIFIC LEADS TO ENHANCED  
PROBABILITIES OF ABOVE NORMAL PRECIPITATION FOR THE WEST COAST OF THE CONUS. AS  
A TROUGH PROGRESSES FROM WEST TO EAST FROM THE NORTH-CENTRAL TO THE  
NORTHEASTERN CONUS, NEAR TO ABOVE NORMAL PRECIPITATION IS FAVORED FOR MUCH OF  
THE EASTERN CONUS. WEAK RIDGING LEADS TO ENHANCED PROBABILITIES OF BELOW NORMAL  
PRECIPITATION FOR MUCH OF THE WEST-CENTRAL CONUS. ENHANCED WESTERLY 500-HPA  
FLOW AND THE POTENTIAL FOR SHORTWAVE TROUGHS LEAD TO INCREASED PROBABILITIES OF  
ABOVE NORMAL PRECIPITATION FOR MAINLAND ALASKA AND THE ALEUTIANS.  
 
THE OFFICIAL 6-10 DAY 500-HPA HEIGHT BLEND CONSISTS OF 15% OF TODAY'S 0Z GFS  
ENSEMBLE MEAN CENTERED ON DAY 8, 20% OF TODAY'S 6Z GFS ENSEMBLE MEAN CENTERED  
ON DAY 8, 10% OF TODAY'S OPERATIONAL 0Z GFS 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, 5% OF YESTERDAY'S 12Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY  
7, 5% OF TODAY'S OPERATIONAL 0Z ECMWF CENTERED ON DAY 8, AND 10% OF TODAY'S 0Z  
CANADIAN ENSEMBLE MEAN CENTERED ON DAY 8  
 
 
FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: AVERAGE, 3 OUT OF 5, DUE TO FAIR  
MODEL AGREEMENT.  
 
8-14 DAY OUTLOOK FOR MAR 08 - 14 2018  
 
DURING THE WEEK-2 PERIOD POSITIVE 500-HPA HEIGHT ANOMALIES CONTINUE OVER MUCH  
OF THE HIGH LATITUDES DUE TO RIDGES SOUTH OF THE ALEUTIANS AND NEAR HUDSON BAY.  
BETWEEN THESE TWO FEATURES, HEIGHTS ARE EXPECTED TO LOWER OVER MAINLAND ALASKA  
AS TROUGHS ARE EXPECTED NEAR THE BERING STRAIT AS WELL AS OVER THE GULF OF  
ALASKA. THE TROUGH OVER THE GULF OF ALASKA IS FORECAST TO EXTEND SOUTHWARD OVER  
THE EASTERN PACIFIC, OFF THE WEST COAST OF THE CONUS, ALLOWING FOR A WEAK RIDGE  
TO DEVELOP DOWNSTREAM OVER PARTS OF THE WEST-CENTRAL CONUS. CYCLONIC FLOW IS  
EXPECTED FARTHER TO THE EAST OVER THE EASTERN CONUS. THE GREATEST WEIGHT IN THE  
WEEK-2 MANUAL 500-HPA HEIGHT BLEND WAS GIVEN TO THE 0Z ECMWF ENSEMBLE MEAN  
SOLUTION DUE TO CONSIDERATIONS OF RECENT SKILL.  
 
BELOW NORMAL TEMPERATURES ARE FAVORED FOR MUCH OF THE NORTHWESTERN AND  
SOUTHEASTERN CONUS UNDERNEATH NEAR TO BELOW NORMAL HEIGHTS. HOWEVER, WEAK  
RIDGING LEADS TO ELEVATED CHANCES FOR ABOVE NORMAL TEMPERATURES FOR PARTS OF  
THE SOUTHWEST AND SOUTHERN HIGH PLAINS. ABOVE NORMAL TEMPERATURES ARE SLIGHTLY  
FAVORED FOR PARTS OF THE NORTHEASTERN CONUS AND GREAT LAKES CONSISTENT WITH  
TELECONNECTIONS ASSOCIATED WITH A POSITIVE HEIGHT ANOMALY CENTER EXPECTED NEAR  
HUDSON BAY. TROUGH DEVELOPMENT OVER MAINLAND ALASKA LEADS TO ENHANCED  
PROBABILITIES OF BELOW NORMAL TEMPERATURES ACROSS MUCH OF THE STATE.  
 
THERE ARE ENHANCED PROBABILITIES OF ABOVE NORMAL PRECIPITATION FOR THE WEST  
COAST OF THE CONUS AHEAD OF A TROUGH OVER THE EASTERN PACIFIC. PROBABILITIES OF  
ABOVE NORMAL PRECIPITATION ARE ELEVATED FOR MUCH OF THE SOUTHEASTERN CONUS  
EXTENDING NORTHWESTWARD TO THE MIDDLE MISSISSIPPI VALLEY UNDERNEATH CYCLONIC  
FLOW AND CONSISTENT WITH TELECONNECTIONS FROM THE EXPECTED POSITIVE HEIGHT  
ANOMALY CENTER NEAR HUDSON BAY. ABOVE NORMAL PRECIPITATION IS SLIGHTLY FAVORED  
FOR EASTERN NEW ENGLAND AHEAD OF THE TROUGH FORECAST OVER THE EASTERN CONUS.  
BELOW NORMAL PRECIPITATION IS FAVORED FOR MUCH OF THE GREAT LAKES REGION DUE TO  
SUBSIDENCE BEHIND THE MEAN TROUGH AXIS. WEAK RIDGING SLIGHTLY FAVORS NEAR TO  
BELOW NORMAL PRECIPITATION ACROSS THE WEST-CENTRAL CONUS. THE POTENTIAL FOR  
SHORTWAVE ENERGY ASSOCIATED WITH TROUGHS NEAR THE BERING STRAIT AND GULF OF  
ALASKA LEAD TO INCREASED PROBABILITIES OF ABOVE NORMAL PRECIPITATION FOR MUCH  
OF ALASKA.  
 
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, 10% OF TODAY'S OPERATIONAL 0Z GFS CENTERED ON DAY 11, 45% OF TODAY'S  
0Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 11, 5% 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: BELOW AVERAGE, 2 OUT OF 5, DUE TO  
RELATIVELY POOR AGREEMENT AMONG THE SURFACE TOOLS TOOLS ACROSS MUCH OF THE  
FORECAST DOMAIN.  
 
FORECASTER: SCOTT H  
 
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  
MARCH 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:  
19630314 - 19940210 - 19900212 - 19570208 - 19550312  
 
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:  
19900211 - 19550312 - 20090312 - 19630313 - 19570208  
 
6-10 DAY OUTLOOK TABLE  
OUTLOOK FOR MAR 06 - 10 2018  
 
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN  
WASHINGTON B A OREGON B A NRN CALIF B A  
SRN CALIF N A IDAHO B N NEVADA B N  
W MONTANA B B E MONTANA B B WYOMING B B  
UTAH B N ARIZONA N B COLORADO N B  
NEW MEXICO A B N DAKOTA B N S DAKOTA B B  
NEBRASKA B B KANSAS B B OKLAHOMA B B  
N TEXAS B B S TEXAS N N W TEXAS A B  
MINNESOTA B A IOWA B N MISSOURI B N  
ARKANSAS B N LOUISIANA B A WISCONSIN N A  
ILLINOIS B N MISSISSIPPI B A MICHIGAN N N  
INDIANA B N OHIO N N KENTUCKY B N  
TENNESSEE B N ALABAMA B A NEW YORK N A  
VERMONT A A NEW HAMP A A MAINE A A  
MASS A A CONN N A RHODE IS N A  
PENN N A NEW JERSEY N A W VIRGINIA B N  
MARYLAND B A DELAWARE N A VIRGINIA B N  
N CAROLINA B N S CAROLINA B N GEORGIA B A  
FL PNHDL B A FL PENIN B A AK N SLOPE N A  
AK ALEUTIAN A A AK WESTERN A A AK INT BSN N A  
AK S INT B A AK SO COAST B A AK PNHDL B N  
 
 
 
8-14 DAY OUTLOOK TABLE  
OUTLOOK FOR MAR 08 - 14 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 B A NEVADA B A  
W MONTANA B N E MONTANA B N WYOMING B N  
UTAH B A ARIZONA A N COLORADO N N  
NEW MEXICO A B N DAKOTA B N S DAKOTA B N  
NEBRASKA N N KANSAS N N OKLAHOMA N B  
N TEXAS N B S TEXAS A B W TEXAS A B  
MINNESOTA N N IOWA N N MISSOURI B A  
ARKANSAS B A LOUISIANA N N WISCONSIN N B  
ILLINOIS B A MISSISSIPPI B A MICHIGAN N B  
INDIANA B B OHIO B B KENTUCKY B N  
TENNESSEE B A ALABAMA B A NEW YORK N N  
VERMONT N N NEW HAMP N N MAINE A N  
MASS N A CONN N N RHODE IS N N  
PENN B N NEW JERSEY B N W VIRGINIA B N  
MARYLAND B N DELAWARE B N VIRGINIA B N  
N CAROLINA B N S CAROLINA B A GEORGIA B A  
FL PNHDL B A FL PENIN B A AK N SLOPE B A  
AK ALEUTIAN N A AK WESTERN B A AK INT BSN B A  
AK S INT B A AK SO COAST B A AK PNHDL B A  
 
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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