028  
FXUS06 KWBC 082001  
PMDMRD  
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS  
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD  
300 PM EST THU MARCH 08 2018  
 
6-10 DAY OUTLOOK FOR MAR 14 - 18 2018  
 
TODAY'S ENSEMBLE MEAN SOLUTIONS ARE IN GOOD AGREEMENT ON THE EXPECTED LARGE  
SCALE 500-HPA CIRCULATION PATTERN IN THE 6-10 DAY PERIOD. A HIGH AMPLITUDE  
RIDGE IS PREDICTED OVER THE ALEUTIANS AND THE GULF OF ALASKA, AND A DEEP TROUGH  
IS PREDICTED OFF THE PACIFIC COAST. DOWNSTREAM, A RIDGE IS PREDICTED OVER  
CENTRAL NORTH AMERICA WITH A TROUGH OVER THE ATLANTIC COAST. BELOW NORMAL  
500-HPA HEIGHTS ARE PREDICTED OVER THE WESTERN AND EASTERN CONUS, AS WELL AS  
PARTS OF NORTHERN MAINLAND ALASKA. NEAR TO ABOVE NORMAL 500-HPA HEIGHTS ARE  
FORECAST FOR THE CENTRAL CONUS AND MOST OF SOUTHERN AND CENTRAL ALASKA, THE  
ALASKA PANHANDLE, AND THE ALEUTIANS.  
 
TROUGHING IN THE EASTERN PACIFIC LEADS TO INCREASED CHANCES FOR BELOW NORMAL  
TEMPERATURES FOR THE MUCH OF WESTERN CONUS. A RIDGE FORECAST OVER CENTRAL NORTH  
AMERICA LEADS TO ENHANCED CHANCES OF ABOVE NORMAL TEMPERATURES FOR MUCH OF THE  
SOUTH-CENTRAL CONUS, AND PART OF THE GREAT LAKES REGION. ANOMALOUS TROUGHING  
OVER THE ATLANTIC COAST AND NORTHERLY FLOW TILT THE ODDS TO BELOW NORMAL  
TEMPERATURES FOR THE EASTERN CONUS. BELOW NORMAL TEMPERATURES ARE FAVORED FOR  
PARTS OF MONTANA AND NORTH DAKOTA ASSOCIATED WITH SNOW COVER. ABOVE NORMAL  
500-HPA HEIGHTS OVER ALASKA FAVOR ABOVE NORMAL TEMPERATURES OVER NORTHERN AND  
WESTERN MAINLAND ALASKA AND THE ALEUTIANS, WHILE BELOW NORMAL TEMPERATURES ARE  
FAVORED FOR SOUTHERN MAINLAND ALASKA AND PART OF THE ALASKA PANHANDLE.  
 
MOIST FLOW AHEAD OF A TROUGH IN THE EASTERN PACIFIC LEADS TO ENHANCED  
PROBABILITIES OF ABOVE NORMAL PRECIPITATION FOR THE WESTERN CONUS, AND THE  
NORTHERN GREAT PLAINS, AND UPPER MISSISSIPPI VALLEY. THE POTENTIAL FOR  
SHORTWAVE ENERGY ASSOCIATED WITH ENHANCED WESTERLY 500-HPA FLOW LEADS TO  
INCREASED PROBABILITIES OF ABOVE NORMAL PRECIPITATION FOR MOST OF MAINLAND  
ALASKA AND THE ALEUTIANS. RIDGING LEADS TO ENHANCED PROBABILITIES OF BELOW  
NORMAL PRECIPITATION FOR MUCH OF THE SOUTH-CENTRAL CONUS, THE GULF COAST  
REGION, AND THE ATLANTIC COAST STATES.  
 
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  
GOOD MODEL AGREEMENT AND THE HIGH AMPLITUDE 500-HPA PATTERN.  
 
8-14 DAY OUTLOOK FOR MAR 16 - 22 2018  
 
THE MEAN 500-HPA FLOW PATTERN EXPECTED FOR THE WEEK-2 PERIOD FEATURES A LESS  
AMPLIFIED CIRCULATION AND THE OVERALL LONG WAVE PATTERN IS SHIFTED EASTWARD,  
ESPECIALLY WITH THE WEAKENING RIDGE OVER THE EAST-CENTRAL CONUS. BELOW NORMAL  
HEIGHTS ARE EXPECTED OVER MUCH OF THE WESTERN, CENTRAL AND NORTHEASTERN CONUS,  
WHILE NEAR TO ABOVE NORMAL HEIGHTS ARE ANTICIPATED OVER MUCH OF THE  
SOUTHEASTERN CONUS, MUCH OF MAINLAND ALASKA, AND THE ALEUTIANS.  
 
BELOW NORMAL TEMPERATURES ARE FAVORED FOR SOUTHEASTERN MAINLAND ALASKA, AND THE  
ALASKA PANHANDLE, WHILE ABOVE NORMAL TEMPERATURES ARE FAVORED FOR WESTERN  
MAINLAND ALASKA AND THE ALEUTIANS. TROUGHING IN THE EASTERN PACIFIC LEADS TO  
INCREASED CHANCES FOR BELOW NORMAL TEMPERATURES FOR THE WESTERN CONUS AND THE  
NORTHERN PLAINS UNDERNEATH NEAR TO BELOW NORMAL HEIGHTS, WHILE RIDGING LEADS TO  
ELEVATED CHANCES FOR ABOVE NORMAL TEMPERATURES FOR THE CENTRAL AND SOUTHERN  
PLAINS, AND THE SOUTHEASTERN CONUS. BELOW NORMAL TEMPERATURES ARE SLIGHTLY  
ENHANCED FOR PARTS OF THE MID ATLANTIC AND NORTHEAST BEHIND THE TROUGH OVER THE  
ATLANTIC.  
 
THERE ARE ENHANCED PROBABILITIES OF ABOVE NORMAL PRECIPITATION FOR THE WESTERN  
CONUS ASSOCIATED WITH ONSHORE FLOW AND TROUGHING. PROBABILITIES OF ABOVE NORMAL  
PRECIPITATION ARE FAVORED FOR MAINLAND ALASKA AND THE ALEUTIANS DUE TO STORM  
SYSTEMS NEAR THE WEST COAST OF MAINLAND ALASKA. ABOVE NORMAL PRECIPITATION IS  
FAVORED FOR THE NORTHERN AND CENTRAL PLAINS, THE MISSISSIPPI VALLEY, AND  
TENNESSEE VALLEY, WHILE BELOW NORMAL PRECIPITATION IS FAVORED FOR THE SOUTHERN  
HIGH PLAINS, CONSISTENT WITH DYNAMICAL MODEL GUIDANCE FROM THE GFS AND ECMWF  
ENSEMBLE MEMBERS. PROBABILITIES OF BELOW NORMAL PRECIPITATION ARE ELEVATED FOR  
THE ATLANTIC COAST STATES BEHIND THE TROUGH OVER THE ATLANTIC.  
 
THE OFFICIAL 8-14 DAY 500-HPA HEIGHT BLEND CONSISTS OF: 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, 20% OF YESTERDAY'S 12Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 10, AND 20%  
OF TODAY'S 0Z CANADIAN ENSEMBLE MEAN CENTERED ON DAY 11  
 
FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD: AVERAGE, 3 OUT OF 5, DUE TO FAIR  
AGREEMENT AMONG THE SURFACE TOOLS ACROSS MUCH OF THE FORECAST DOMAIN.  
 
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  
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:  
20060322 - 20090218 - 19580321 - 19620303 - 20010320  
 
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:  
20090219 - 19580321 - 20060321 - 19580316 - 19620305  
 
6-10 DAY OUTLOOK TABLE  
OUTLOOK FOR MAR 14 - 18 2018  
 
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN  
WASHINGTON N A OREGON B A NRN CALIF B A  
SRN CALIF B A IDAHO N A NEVADA B A  
W MONTANA N A E MONTANA B A WYOMING A A  
UTAH N A ARIZONA B A COLORADO A A  
NEW MEXICO A A N DAKOTA B A S DAKOTA N A  
NEBRASKA A A KANSAS A B OKLAHOMA A B  
N TEXAS A B S TEXAS A B W TEXAS A B  
MINNESOTA A A IOWA A A MISSOURI A A  
ARKANSAS A N LOUISIANA N B WISCONSIN A A  
ILLINOIS A A MISSISSIPPI N B MICHIGAN N A  
INDIANA N A OHIO B N KENTUCKY N N  
TENNESSEE B N ALABAMA B B NEW YORK B N  
VERMONT B B NEW HAMP B B MAINE B N  
MASS B B CONN B B RHODE IS B B  
PENN B N NEW JERSEY B B W VIRGINIA B N  
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 A AK INT BSN A A  
AK S INT B A AK SO COAST B A AK PNHDL N B  
 
 
 
8-14 DAY OUTLOOK TABLE  
OUTLOOK FOR MAR 16 - 22 2018  
 
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN  
WASHINGTON N N OREGON B A NRN CALIF B A  
SRN CALIF B A IDAHO B A NEVADA B A  
W MONTANA B A E MONTANA B A WYOMING B A  
UTAH B A ARIZONA B A COLORADO B A  
NEW MEXICO B A N DAKOTA B A S DAKOTA B A  
NEBRASKA B A KANSAS A A OKLAHOMA A B  
N TEXAS A N S TEXAS A N W TEXAS A B  
MINNESOTA B A IOWA N A MISSOURI N A  
ARKANSAS A A LOUISIANA A N WISCONSIN N A  
ILLINOIS N A MISSISSIPPI A N MICHIGAN N N  
INDIANA N A OHIO N N KENTUCKY N N  
TENNESSEE N N ALABAMA A N NEW YORK N B  
VERMONT N B NEW HAMP N B MAINE N B  
MASS N B CONN N B RHODE IS N B  
PENN N B NEW JERSEY N B W VIRGINIA N N  
MARYLAND N B DELAWARE N B VIRGINIA N N  
N CAROLINA N N S CAROLINA N N GEORGIA A N  
FL PNHDL A N FL PENIN A B AK N SLOPE N A  
AK ALEUTIAN A A AK WESTERN A A AK INT BSN B A  
AK S INT B N AK SO COAST B N 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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