PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS 
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD 
300 PM EDT THU JUNE 21 2018 
 
6-10 DAY OUTLOOK FOR JUN 27 - JUL 01, 2018 
 
TODAY'S MODEL SOLUTIONS ARE IN FAIRLY GOOD AGREEMENT ON THE OVERALL 500-HPA  
FLOW PATTERN OVER THE FORECAST DOMAIN. AT THE BEGINNING OF THE PERIOD, MODELS  
DEPICT TROUGHS OVER THE BERING SEA AND WESTERN MAINLAND ALASKA, AND OVER PARTS  
OF CENTRAL CANADA INTO THE WESTERN CONUS. A WEAK RIDGE IS EXPECTED OVER THE  
EASTERN PACIFIC AND OVER MUCH OF THE SOUTHERN U.S. THE MANUAL 500-HPA HEIGHT  
BLEND FOR THE FIVE DAY PERIOD, BASED PRIMARILY ON THE LATEST ENSEMBLE MEAN  
SOLUTIONS FROM THE GEFS AND ECMWF, DEPICTS ABOVE NORMAL HEIGHTS OVER MOST OF  
THE CONUS, EXCEPT FOR NEAR TO BELOW NORMAL HEIGHTS OVER PARTS OF THE NORTHERN  
PLAINS. NEAR NORMAL HEIGHTS ARE EXPECTED OVER ALASKA. 
 
ABOVE NORMAL TEMPERATURES ARE FAVORED FOR MOST OF THE CONUS UNDERNEATH NEAR TO  
ABOVE NORMAL HEIGHTS. HOWEVER, ENHANCED PROBABILITIES OF NEAR TO BELOW NORMAL  
TEMPERATURES ARE INDICATED FOR PARTS OF THE NORTHWESTERN CONUS AS A PREDICTED  
TROUGH PUSHES INLAND BY THE END OF THE PERIOD. BELOW NORMAL TEMPERATURES ARE  
FAVORED FOR SOUTHERN MAINLAND ALASKA AND THE ALASKA PANHANDLE, AND ABOVE NORMAL  
TEMPERATURES ARE FAVORED ELSEWHERE FOR ALASKA, CONSISTENT WITH DYNAMICAL MODEL  
TEMPERATURE TOOLS. 
 
A PERSISTENT STORM SYSTEM PREDICTED OVER ALASKA DURING A PORTION OF THE 6-10  
DAY PERIOD LEADS TO ENHANCED PROBABILITIES OF ABOVE NORMAL PRECIPITATION FOR  
WESTERN AND SOUTHERN PORTIONS OF THE STATE. BELOW NORMAL PRECIPITATION IS  
FAVORED FOR THE NORTHWESTERN CONUS IN ASSOCIATION WITH ANTICIPATED SURFACE HIGH  
PRESSURE UPSTREAM OVER THE EASTERN NORTH PACIFIC. THERE ARE ENHANCED  
PROBABILITIES OF ABOVE NORMAL PRECIPITATION FROM THE NORTHERN AND CENTRAL  
PLAINS EXTENDING EASTWARD TO THE GREAT LAKES AND OHIO VALLEY AS A FORECAST  
SHORTWAVE TROUGH PROGRESSES THROUGH THESE REGIONS. RIDGING OVER EASTERN CANADA  
LEADS TO ENHANCED PROBABILITIES OF BELOW NORMAL PRECIPITATION FOR PARTS OF THE  
NORTHEASTERN CONUS. ABOVE NORMAL PRECIPITATION IS FAVORED FOR PARTS OF THE  
SOUTHEASTERN CONUS DUE TO THE POTENTIAL FOR MOIST FLOW AROUND SURFACE HIGH  
PRESSURE CENTERED OVER THE ATLANTIC AND DUE TO AN ANTICIPATED FRONTAL BOUNDARY.  
BELOW NORMAL PRECIPITATION IS SLIGHTLY FAVORED FARTHER TO THE WEST FOR PARTS OF  
THE SOUTHERN PLAINS, CONSISTENT WITH DYNAMICAL MODEL GUIDANCE. 
 
THE OFFICIAL 6-10 DAY 500-HPA HEIGHT BLEND CONSISTS OF 40% OF TODAY'S 6Z GFS  
ENSEMBLE MEAN CENTERED ON DAY 8, 20% OF TODAY'S OPERATIONAL 6Z GFS CENTERED ON  
DAY 8, AND 40% OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 8  
  
 
FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: ABOVE AVERAGE, 4 OUT OF 5, DUE TO  
FAIRLY GOOD MODEL AND TOOL AGREEMENT. 
 
8-14 DAY OUTLOOK FOR JUN 29 - JUL 05, 2018  
 
BY THE WEEK-2 PERIOD, MODELS SUGGEST THAT THE 500-HPA PATTERN WILL RETROGRADE A  
BIT, WITH HEIGHTS REMAINING ABOVE NORMAL ACROSS THE ENTIRE U.S. ABOVE NORMAL  
TEMPERATURES ARE AGAIN FAVORED FOR MOST OF THE CONUS, UNDER ABOVE NORMAL  
500-HPA HEIGHTS. HOWEVER, NEAR TO BELOW NORMAL TEMPERATURES ARE FAVORED FOR  
PARTS OF THE NORTHERN ROCKIES AND PLAINS DUE TO A PREDICTED TROUGH. BELOW  
NORMAL TEMPERATURES ARE NO LONGER FAVORED FOR PARTS OF ALASKA DUE TO THE SLIGHT  
INCREASE IN PREDICTED HEIGHTS OVER ALASKA BY THE WEEK-2 PERIOD. 
 
PERSISTENT TROUGHING OVER THE BERING SEA LEADS TO SLIGHTLY ENHANCED  
PROBABILITIES OF ABOVE NORMAL PRECIPITATION ACROSS MUCH OF ALASKA. STRONG  
SURFACE HIGH PRESSURE OVER THE EASTERN NORTH PACIFIC AND ASSOCIATED NORTHERLY,  
LOW-LEVEL FLOW FAVOR BELOW NORMAL PRECIPITATION ACROSS MUCH OF THE NORTHWESTERN  
CONUS. THERE ARE ENHANCED PROBABILITIES OF ABOVE NORMAL PRECIPITATION FARTHER  
TO THE EAST FOR PARTS OF THE NORTH-CENTRAL CONUS EAST OF THE TROUGH PREDICTED  
OVER THE NORTHWESTERN CONUS. SUBTROPICAL RIDGING LEADS TO FAVORED BELOW NORMAL  
PRECIPITATION FOR THE SOUTHERN PLAINS. DYNAMICAL MODEL GUIDANCE FROM THE 0Z  
ECMWF ENSEMBLE MEAN AS WELL AS ANALOGS FROM THE MANUAL HEIGHT BLEND GENERALLY  
FAVOR ABOVE NORMAL PRECIPITATION ACROSS MUCH OF THE SOUTHEASTERN CONUS.  
ENHANCED PROBABILITIES OF ABOVE NORMAL PRECIPITATION ARE ALSO DEPICTED FOR  
PARTS OF THE SOUTHWEST MONSOON REGION, SOUTH OF THE MEAN 500-HPA RIDGE AXIS  
FORECAST BY THE 0Z ECMWF ENSEMBLE MEAN. 
 
THE OFFICIAL 8-14 DAY 500-HPA HEIGHT BLEND CONSISTS OF: 40% OF TODAY'S 6Z GFS  
ENSEMBLE MEAN CENTERED ON DAY 11, 20% OF TODAY'S OPERATIONAL 6Z GFS CENTERED ON  
DAY 11, AND 40% OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 11  
 
 
FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD: ABOVE AVERAGE, 4 OUT OF 5, DUE TO  
FAIRLY GOOD MODEL AND TOOL AGREEMENT. 
 
FORECASTER: MIKE C 
 
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  
JULY 19. 
 
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:  
19980702 - 19750703 - 20060611 - 19770616 - 19870629 
 
 
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:  
19980702 - 20060612 - 19750704 - 19770615 - 20020611 
 
 
6-10 DAY OUTLOOK TABLE 
OUTLOOK FOR JUN 27 - JUL 01, 2018 
 
STATE      TEMP PCPN   STATE      TEMP PCPN   STATE      TEMP PCPN    
WASHINGTON  N    B     OREGON      A    B     NRN CALIF   A    N      
SRN CALIF   A    N     IDAHO       N    B     NEVADA      A    N      
W MONTANA   B    B     E MONTANA   B    A     WYOMING     N    N      
UTAH        A    B     ARIZONA     A    N     COLORADO    A    B      
NEW MEXICO  A    B     N DAKOTA    A    A     S DAKOTA    A    A      
NEBRASKA    A    N     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    N      
ARKANSAS    A    N     LOUISIANA   A    N     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    A    A      
VERMONT     A    B     NEW HAMP    A    B     MAINE       A    B      
MASS        A    B     CONN        A    B     RHODE IS    A    B      
PENN        A    A     NEW JERSEY  A    N     W VIRGINIA  A    A      
MARYLAND    A    A     DELAWARE    A    N     VIRGINIA    A    A      
N CAROLINA  A    N     S CAROLINA  A    N     GEORGIA     A    N      
FL PNHDL    A    N     FL PENIN    A    N     AK N SLOPE  A    N      
AK ALEUTIAN A    A     AK WESTERN  A    A     AK INT BSN  A    N      
AK S INT    B    A     AK SO COAST B    A     AK PNHDL    B    A      
  
                            
 
8-14 DAY OUTLOOK TABLE 
OUTLOOK FOR JUN 29 - JUL 05, 2018 
 
STATE      TEMP PCPN   STATE      TEMP PCPN   STATE      TEMP PCPN    
WASHINGTON  A    B     OREGON      A    B     NRN CALIF   A    N      
SRN CALIF   N    N     IDAHO       N    N     NEVADA      A    N      
W MONTANA   B    A     E MONTANA   A    A     WYOMING     A    A      
UTAH        A    N     ARIZONA     A    A     COLORADO    A    N      
NEW MEXICO  A    A     N DAKOTA    A    A     S DAKOTA    A    A      
NEBRASKA    A    N     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    N      
ARKANSAS    A    N     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    A    N      
VERMONT     A    N     NEW HAMP    A    N     MAINE       A    N      
MASS        A    N     CONN        A    N     RHODE IS    A    N      
PENN        A    A     NEW JERSEY  A    N     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    N     FL PENIN    A    N     AK N SLOPE  A    N      
AK ALEUTIAN A    A     AK WESTERN  N    A     AK INT BSN  N    N      
AK S INT    N    A     AK SO COAST N    A     AK PNHDL    N    N      
  
                           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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