170  
FXUS06 KWBC 072002  
PMDMRD  
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS  
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD  
300 PM EST WED MARCH 07 2018  
 
6-10 DAY OUTLOOK FOR MAR 13 - 17 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 A DEEP TROUGH IS PREDICTED OFF THE  
PACIFIC COAST. DOWNSTREAM, A STRONG RIDGE IS PREDICTED OVER CENTRAL NORTH  
AMERICA WITH A TROUGH OVER THE ATLANTIC COAST. BELOW NORMAL 500-HPA HEIGHTS ARE  
PREDICTED OVER THE WEST COAST OF THE CONUS, AND THE EASTERN CONUS. ABOVE NORMAL  
500-HPA HEIGHTS ARE FORECAST FOR THE CENTRAL CONUS AND MOST OF ALASKA.  
 
TROUGHING IN THE EASTERN PACIFIC LEADS TO INCREASED CHANCES FOR BELOW NORMAL  
TEMPERATURES FOR SOUTHERN ALASKA AND THE MUCH OF THE WEST COAST OF THE CONUS. A  
RIDGE FORECAST OVER CENTRAL NORTH AMERICA LEADS TO ENHANCED CHANCES OF ABOVE  
NORMAL TEMPERATURES FOR MUCH OF THE WEST-CENTRAL CONUS, AND PART OF THE GREAT  
LAKES REGION, EXCEPT FOR PARTS OF MONTANA AND NORTH DAKOTA. ANOMALOUS TROUGHING  
OVER THE ATLANTIC COAST AND NORTHERLY FLOW TILT THE ODDS TO BELOW NORMAL  
TEMPERATURES FROM THE EASTERN CONUS TO PARTS OF THE SOUTHERN PLAINS. ABOVE  
NORMAL 500-HPA HEIGHTS OVER ALASKA FAVOR ABOVE NORMAL TEMPERATURES OVER  
NORTHERN AND WESTERN MAINLAND ALASKA AND THE ALEUTIANS.  
 
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. 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 AND EASTERN CONUS.  
 
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 15 - 21 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 TROUGH MOVING OVER THE ATLANTIC. BELOW NORMAL HEIGHTS ARE  
EXPECTED OVER MUCH OF THE WESTERN AND CENTRAL CONUS AND THE MIDDLE AND NORTH  
ATLANTIC COAST STATES, WHILE NEAR TO ABOVE NORMAL HEIGHTS ARE ANTICIPATED OVER  
MUCH OF THE EAST-CENTRAL CONUS, SOUTHWESTERN MAINLAND ALASKA, AND THE  
ALEUTIANS.  
 
BELOW NORMAL TEMPERATURES ARE FAVORED FOR MUCH OF SOUTHEASTERN MAINLAND ALASKA,  
THE ALASKA PANHANDLE, THE WESTERN CONUS, AND THE NORTHERN PLAINS UNDERNEATH  
NEAR TO BELOW NORMAL HEIGHTS. HOWEVER, RIDGING LEADS TO ELEVATED CHANCES FOR  
ABOVE NORMAL TEMPERATURES FOR THE CENTRAL AND SOUTHERN PLAINS NORTHEASTWARD TO  
PARTS OF THE GREAT LAKES, AND THE MISSISSIPPI VALLEY. 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 SOUTH COAST. ABOVE NORMAL PRECIPITATION IS FAVORED FOR THE  
NORTHERN PLAINS AND THE UPPER MISSISSIPPI VALLEY, THE GREAT LAKES, THE OHIO  
VALLEY, AND TENNESSEE VALLEY, WHILE BELOW NORMAL PRECIPITATION IS FAVORED FOR  
THE SOUTHERN HIGH PLAINS, CONSISTENT WITH DYNAMICAL MODEL GUIDANCE FROM THE GFS  
ENSEMBLE MEMBERS. PROBABILITIES OF BELOW NORMAL PRECIPITATION ARE ELEVATED FOR  
THE MIDDLE AND SOUTHERN 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:  
20060321 - 20090217 - 19580308 - 19580314 - 19620303  
 
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:  
20060320 - 20090218 - 19620305 - 19580313 - 19580307  
 
6-10 DAY OUTLOOK TABLE  
OUTLOOK FOR MAR 13 - 17 2018  
 
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN  
WASHINGTON A A OREGON B A NRN CALIF B A  
SRN CALIF B A IDAHO A A NEVADA B A  
W MONTANA N A E MONTANA B A WYOMING A A  
UTAH A A ARIZONA A A COLORADO A B  
NEW MEXICO A A N DAKOTA N N S DAKOTA A A  
NEBRASKA A B KANSAS A B OKLAHOMA A B  
N TEXAS B B S TEXAS B B W TEXAS A B  
MINNESOTA A N IOWA A N MISSOURI A B  
ARKANSAS B B LOUISIANA B B WISCONSIN A B  
ILLINOIS N B MISSISSIPPI B B MICHIGAN N B  
INDIANA B B OHIO B B KENTUCKY B B  
TENNESSEE B B ALABAMA B B NEW YORK B B  
VERMONT B B NEW HAMP B B MAINE N B  
MASS B B CONN B B RHODE IS B B  
PENN B B NEW JERSEY B B W VIRGINIA B B  
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 N A  
AK S INT B A AK SO COAST B A AK PNHDL N B  
 
 
 
8-14 DAY OUTLOOK TABLE  
OUTLOOK FOR MAR 15 - 21 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 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 A A KANSAS A B OKLAHOMA A B  
N TEXAS A B S TEXAS A N W TEXAS A B  
MINNESOTA N A IOWA A A MISSOURI A A  
ARKANSAS A A LOUISIANA A A WISCONSIN A 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 B A  
VERMONT B N NEW HAMP B N MAINE N N  
MASS B N CONN B N RHODE IS B N  
PENN N A NEW JERSEY B N W VIRGINIA N A  
MARYLAND N N DELAWARE B N VIRGINIA N N  
N CAROLINA N N S CAROLINA N N GEORGIA A A  
FL PNHDL A B FL PENIN N B AK N SLOPE N A  
AK ALEUTIAN A A AK WESTERN N A AK INT BSN B A  
AK S INT B A 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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