6-10 Day Narrative

926 
FXUS06 KWBC 282006
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EST TUE FEBRUARY 28 2017
6-10 DAY OUTLOOK FOR MAR 06 - 10 2017
TODAY'S DYNAMICAL MODELS ARE IN FAIR AGREEMENT ON THE 500-HPA FLOW PATTERN OVER 
THE FORECAST DOMAIN. AN AMPLIFIED PATTERN IS PREDICTED OVER ALASKA AS A STRONG 
RIDGE IS FORECAST OVER THE WESTERN ALEUTIANS AND A DEEP TROUGH IS PREDICTED TO 
DOMINATE MUCH OF THE REMAINDER OF THE STATE. A LOWER AMPLITUDE PATTERN IS 
FORECAST FARTHER TO THE SOUTH OVER THE CONUS. ABOVE NORMAL HEIGHTS ARE FORECAST 
OVER MOST OF THE SOUTHERN TWO-THIRDS OF THE CONUS. TROUGHS AND BELOW NORMAL 
HEIGHTS ARE FORECAST OVER THE NORTHEASTERN CONUS AND NEAR THE PACIFIC 
NORTHWEST. ENSEMBLE SPREAD IS MODERATELY HIGH OVER MUCH OF THE CONUS, 
INDICATING THAT THERE ARE DIFFERENCES AMONG INDIVIDUAL ENSEMBLE MEMBERS IN 
RESOLVING SHORTWAVE FEATURES OVER MUCH OF THE COUNTRY. DUE, IN PART, TO THESE 
DIFFERENCES, THE ENSEMBLE MEAN SOLUTIONS WERE GIVEN THE MAJORITY OF THE WEIGHT 
IN TODAY'S 500-HPA MANUAL HEIGHT BLEND. THE GREATEST WEIGHT WAS GIVEN TO 
TODAY'S 0Z GFS ENSEMBLE MEAN DUE TO CONSIDERATIONS OF RECENT SKILL AND ANALOG 
CORRELATIONS (WHICH MEASURE HOW CLOSELY THE FORECAST PATTERN MATCHES CASES THAT 
HAVE OCCURRED IN THE PAST). 
BELOW NORMAL TEMPERATURES ARE STRONGLY FAVORED FOR MUCH OF ALASKA DUE TO THE 
DEEP TROUGH PREDICTED TO DOMINATE THE STATE. ENHANCED PROBABILITIES FOR BELOW 
NORMAL TEMPERATURES ARE ALSO INDICATED FOR THE NORTHWESTERN CONUS, CONSISTENT 
WITH BIAS-CORRECTED DYNAMICAL MODEL GUIDANCE FROM THE GEFS, ECMWF, AND CANADIAN 
ENSEMBLES. ABOVE NORMAL TEMPERATURES ARE FAVORED FOR MOST OF THE REMAINDER OF 
THE CONUS UNDERNEATH PREDICTED NEAR TO ABOVE NORMAL HEIGHTS. THE EXCEPTION IS 
PARTS OF NORTHERN NEW ENGLAND WHERE NEAR NORMAL TEMPERATURES ARE FAVORED IN 
ASSOCIATION WITH A PREDICTED TROUGH.  
THERE ARE INCREASED PROBABILITIES OF ABOVE MEDIAN PRECIPITATION FOR THE 
NORTHWESTERN CONUS DUE TO THE POTENTIAL FOR ENHANCED PACIFIC FLOW. BELOW MEDIAN 
PRECIPITATION IS FAVORED FOR THE SOUTHWESTERN CONUS AND MUCH OF THE CENTRAL 
CONUS UNDERNEATH PREDICTED ABOVE NORMAL HEIGHTS. ABOVE MEDIAN PRECIPITATION IS 
WEAKLY FAVORED FOR THE GREAT LAKES REGION AND PARTS OF THE NORTHEAST IN 
ASSOCIATION WITH A PREDICTED TROUGH. PROBABILITIES FOR BELOW MEDIAN 
PRECIPITATION ARE ELEVATED FOR PARTS OF THE SOUTHEASTERN CONUS IN ASSOCIATION 
WITH PREDICTED SURFACE HIGH PRESSURE. ABOVE MEDIAN PRECIPITATION IS SLIGHTLY 
FAVORED FOR PORTIONS OF SOUTHERN TEXAS DUE TO THE POTENTIAL FOR RETURN FLOW 
AROUND THE PREDICTED SURFACE HIGH. BELOW MEDIAN PRECIPITATION IS FAVORED FOR 
MUCH OF ALASKA DUE TO THE STRONG TROUGH AND ASSOCIATED ANOMALOUS NORTHERLY MID 
LEVEL FLOW PREDICTED OVER THE STATE. HOWEVER, ABOVE MEDIAN PRECIPITATION IS 
FAVORED FOR THE SOUTHERN PANHANDLE DOWNSTREAM OF THE PREDICTED TROUGH AXIS. 
TODAY'S OFFICIAL 500-HPA BLEND CONSISTS OF 35% OF TODAY'S 0Z GFS ENSEMBLE MEAN 
CENTERED ON DAY 8, 15% OF TODAY'S 6Z GFS ENSEMBLE MEAN CENTERED ON DAY 8, 5% OF 
TODAY'S OPERATIONAL 0Z GFS CENTERED ON DAY 8, 5% OF TODAY'S OPERATIONAL 6Z GFS 
CENTERED ON DAY 8, 25% 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 5% OF TODAY'S 0Z CANADIAN ENSEMBLE 
MEAN CENTERED ON DAY 8 
 
FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: BELOW AVERAGE, 2 OUT OF 5, DUE TO 
MODERATELY HIGH ENSEMBLE SPREAD OVER MUCH OF THE CONUS.
8-14 DAY OUTLOOK FOR MAR 08 - 14 2017 
DURING THE WEEK-2 PERIOD, AN AMPLIFIED 500-HPA FLOW PATTERN CONTINUES TO BE 
FORECAST FOR ALASKA. A RIDGE IS PREDICTED OVER THE WESTERN ALEUTIANS WHILE A 
STRONG TROUGH IS FORECAST DOWNSTREAM OVER EASTERN, MAINLAND ALASKA. A LOW 
AMPLITUDE PATTERN AND NEAR TO ABOVE NORMAL HEIGHTS ARE FORECAST OVER MUCH OF 
THE CONUS. HOWEVER, TROUGHS AND SLIGHTLY BELOW NORMAL HEIGHTS ARE PREDICTED FOR 
PARTS OF THE NORTHEASTERN AND NORTHWESTERN CONUS. ENSEMBLE SPREAD IS MODERATELY 
HIGH OVER MUCH OF THE FORECAST DOMAIN AND THERE ARE LARGE DISAGREEMENTS AMONG 
SUCCESSIVE RUNS OF THE DETERMINISTIC GFS. AS A RESULT, THE OFFICIAL 500-HPA 
HEIGHT BLEND FOR THE WEEK-2 PERIOD IS BASED PRIMARILY ON THE ENSEMBLE MEAN 
SOLUTIONS. 
BELOW NORMAL TEMPERATURES ARE STRONGLY FAVORED FOR MOST OF ALASKA DUE TO THE 
DEEP TROUGH PREDICTED OVER THE STATE. THERE ARE ENHANCED PROBABILITIES FOR 
ABOVE NORMAL TEMPERATURES FOR THE SOUTHWESTERN, CENTRAL, AND SOUTHEASTERN CONUS 
DUE TO PREDICTED LOW AMPLITUDE FLOW AND NEAR TO ABOVE NORMAL HEIGHTS. ENHANCED 
PROBABILITIES FOR BELOW NORMAL TEMPERATURES ARE INDICATED FOR PARTS OF THE 
NORTHWESTERN CONUS CONSISTENT WITH BIAS CORRECTED DYNAMICAL MODEL GUIDANCE.  
NEAR NORMAL TEMPERATURES ARE FAVORED FOR THE NORTHEASTERN CONUS DUE TO A WEAK 
TROUGH PREDICTED IN THE VICINITY. ENHANCED PROBABILITIES FOR BELOW NORMAL 
TEMPERATURES WERE REMOVED FOR THE NORTHEASTERN CONUS AS THE AMPLITUDE OF THE 
TROUGH HAS WEAKENED RELATIVE TO YESTERDAY'S OUTLOOK.
ABOVE MEDIAN PRECIPITATION IS FAVORED FOR THE NORTHWESTERN CONUS IN ASSOCIATION 
WITH A TROUGH PREDICTED NEAR THE PACIFIC NORTHWEST. THE POTENTIAL FOR SHORTWAVE 
ENERGY TO TRAVERSE THE NORTHERN TIER OF THE CONUS LEADS TO ENHANCED 
PROBABILITIES FOR ABOVE MEDIAN PRECIPITATION FOR PARTS OF THE NORTHERN PLAINS 
AND GREAT LAKES. BELOW MEDIAN PRECIPITATION IS FAVORED FOR THE SOUTHWESTERN 
CONUS, EXTENDING TO PARTS OF THE CENTRAL CONUS, UNDERNEATH PREDICTED ABOVE 
NORMAL HEIGHTS. ENHANCED PROBABILITIES OF BELOW MEDIAN PRECIPITATION ARE ALSO 
INDICATED FOR MUCH OF THE SOUTHEASTERN CONUS IN ASSOCIATION WITH PREDICTED MEAN 
SURFACE HIGH PRESSURE. THE POTENTIAL FOR RETURN FLOW AROUND THIS HIGH LEADS TO 
A SLIGHT ENHANCEMENT OF ABOVE MEDIAN PRECIPITATION PROBABILITIES FOR PARTS OF 
TEXAS. ANOMALOUS NORTHERLY MID LEVEL FLOW ASSOCIATED WITH THE STRONG TROUGH 
PREDICTED OVER ALASKA LEADS TO ENHANCED PROBABILITIES FOR BELOW MEDIAN 
PRECIPITATION FOR MUCH OF THE STATE. 
THE OFFICIAL 8-14 DAY HEIGHT PROG CONSISTS OF: 30% OF TODAY'S 0Z GFS ENSEMBLE 
MEAN CENTERED ON DAY 11, 25% OF TODAY'S 6Z GFS ENSEMBLE MEAN CENTERED ON DAY 
11, 35% OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 11, 5% OF 
YESTERDAY'S 12Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 10, AND 5% OF TODAY'S 0Z 
CANADIAN ENSEMBLE MEAN CENTERED ON DAY 11 
FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD IS: BELOW AVERAGE, 2 OUT OF 5, DUE 
TO MODERATELY HIGH MODEL SPREAD OVER THE CONUS AND LARGE DISAGREEMENTS AMONG 
THE DETERMINISTIC GFS SOLUTIONS.
FORECASTER: SCOTT HANDEL
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 16
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: 
19900214 - 19590208 - 19670309 - 19550224 - 19630313
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: 
19590207 - 19900214 - 19670309 - 19550224 - 19630313
6-10 DAY OUTLOOK TABLE
OUTLOOK FOR MAR 06 - 10 2017
STATE      TEMP PCPN   STATE      TEMP PCPN   STATE      TEMP PCPN   
WASHINGTON  B    A     OREGON      B    A     NRN CALIF   A    A     
SRN CALIF   A    B     IDAHO       B    A     NEVADA      A    B     
W MONTANA   N    A     E MONTANA   A    N     WYOMING     A    B     
UTAH        A    B     ARIZONA     A    B     COLORADO    A    B     
NEW MEXICO  A    B     N DAKOTA    A    N     S DAKOTA    A    B     
NEBRASKA    A    B     KANSAS      A    B     OKLAHOMA    A    B     
N TEXAS     A    N     S TEXAS     A    N     W TEXAS     A    B     
MINNESOTA   A    A     IOWA        A    B     MISSOURI    A    N     
ARKANSAS    A    N     LOUISIANA   A    N     WISCONSIN   A    A     
ILLINOIS    A    A     MISSISSIPPI A    N     MICHIGAN    A    A     
INDIANA     A    A     OHIO        A    A     KENTUCKY    A    A     
TENNESSEE   A    N     ALABAMA     A    N     NEW YORK    A    A     
VERMONT     A    A     NEW HAMP    A    N     MAINE       N    A     
MASS        A    N     CONN        A    N     RHODE IS    A    N     
PENN        A    N     NEW JERSEY  A    B     W VIRGINIA  A    N     
MARYLAND    A    B     DELAWARE    A    B     VIRGINIA    A    B     
N CAROLINA  A    B     S CAROLINA  A    B     GEORGIA     A    B     
FL PNHDL    A    B     FL PENIN    A    B     AK N SLOPE  B    N     
AK ALEUTIAN B    B     AK WESTERN  B    B     AK INT BSN  B    B     
AK S INT    B    B     AK SO COAST B    B     AK PNHDL    B    N     
 
                           
8-14 DAY OUTLOOK TABLE
OUTLOOK FOR MAR 08 - 14 2017
STATE      TEMP PCPN   STATE      TEMP PCPN   STATE      TEMP PCPN   
WASHINGTON  B    A     OREGON      B    A     NRN CALIF   N    N     
SRN CALIF   A    B     IDAHO       B    A     NEVADA      A    N     
W MONTANA   B    A     E MONTANA   A    A     WYOMING     A    N     
UTAH        A    N     ARIZONA     A    B     COLORADO    A    B     
NEW MEXICO  A    B     N DAKOTA    A    A     S DAKOTA    A    N     
NEBRASKA    A    B     KANSAS      A    B     OKLAHOMA    A    N     
N TEXAS     A    N     S TEXAS     A    A     W TEXAS     A    N     
MINNESOTA   A    A     IOWA        A    N     MISSOURI    A    N     
ARKANSAS    A    N     LOUISIANA   A    B     WISCONSIN   A    A     
ILLINOIS    A    N     MISSISSIPPI A    B     MICHIGAN    A    A     
INDIANA     A    N     OHIO        A    N     KENTUCKY    A    N     
TENNESSEE   A    N     ALABAMA     A    B     NEW YORK    N    N     
VERMONT     N    N     NEW HAMP    N    B     MAINE       N    N     
MASS        N    B     CONN        N    B     RHODE IS    N    B     
PENN        A    N     NEW JERSEY  N    B     W VIRGINIA  A    N     
MARYLAND    A    B     DELAWARE    A    B     VIRGINIA    A    B     
N CAROLINA  A    B     S CAROLINA  A    B     GEORGIA     A    B     
FL PNHDL    A    B     FL PENIN    A    B     AK N SLOPE  B    N     
AK ALEUTIAN B    B     AK WESTERN  B    B     AK INT BSN  B    B     
AK S INT    B    B     AK SO COAST B    B     AK PNHDL    B    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.
$$