PROGNOSTIC DISCUSSIONS FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER CAMP SPRINGS MD
300 PM EDT WED APR 21 2004
 
6 TO 10 DAY OUTLOOK FOR APR 27 - MAY 1 2004
         .         .         .         .         .         .         .
THE MODELS ARE IN GOOD AGREEMENT TODAY DURING THE 6-10 DAY PERIOD IN
DEPICTING A HIGHLY AMPLIFIED CIRCULATION PATTERN OVER THE CONUS. MOST
OF THE COUNTRY...WITH THE EXCEPTION OF THE SOUTHEAST STATES...IS
FORECAST TO HAVE ABOVE NORMAL HEIGHTS WITH THE LARGEST POSITIVE
ANOMALIES CENTERED OVER THE NORTHERN ROCKIES. THE HIGH RESOLUTION
ECMWF FORECASTS LESS PHASING BETWEEN THE NORTHERN AND SOUTHERN 
JETSTREAMS COMPARED TO THE GFS BASED SOLUTIONS...THOUGH IT IS IN
BETTER AGREEMENT WITH THE GFS SOLUTIONS TODAY COMPARED TO YESTERDAY.
THE ECMWF ENSEMBLE MEAN LOOKS TO BE A GOOD COMPROMISE BETWEEN THE
0Z OPERATIONAL GFS AND HIGH RESOLUTION ECMWF SOLUTIONS. THE CANADIAN
ENSEMBLE MEAN IS IN FAIRLY GOOD AGREEMENT WITH THE OTHER MODEL 
SOLUTIONS EXCEPT IT FORECASTS SOME SHORTWAVE ENERGY TO UNDERCUT THE
RIDGE IN THE SOUTHWEST U.S. THE DAVA AND GFS ENSEMBLE MEAN DEPICT 
VERY SIMILAR SOLUTIONS TO EACH OTHER AND ARE IN GOOD AGREEMENT WITH
THE OTHER MODEL SOLUTIONS EXCEPT THEY BOTH DEPICT SLIGHTLY LOWER
HEIGHTS OVER THE EASTERN THIRD OF THE CONUS. THE MODELS SHOW GOOD
CONTINUITY WITH RESPECT TO THEIR SOLUTIONS FROM YESTERDAY...WITH THE
EXCEPTION OF THE HIGH RESOLUTION ECMWF WHICH WAS THE OUTLIER YESTERDAY
...BUT HAS TRENDED BACK TOWARDS THE GFS BASED SOLUTIONS TODAY. ONE 
DIFFERENCE IS THAT THE TROUGH IN THE EASTERN PACIFIC IS FORECAST TO 
BE MUCH STRONGER TODAY COMPARED TO YESTERDAY. THE GFS...CANADIAN AND
ECMWF ENSEMBLE SPAGHETTI DIAGRAMS INDICATE A RELATIVELY LARGE AMOUNT
OF SPREAD TODAY...THOUGH AS USUAL THE ECMWF ENSEMBLE SHOWS RELATIVELY 
LESS SPREAD AMONG ITS MEMBERS. THE PNA INDEX..WHICH RECENTLY HAS 
BEEN VERY WEAKLY NEGATIVE TO NEAR NEUTRAL...IS FORECAST TO REMAIN 
NEAR NEUTRAL THROUGH DAY 14. THE NAO INDEX... WHICH RECENTLY HAS BEEN
WEAKLY POSITIVE IS FORECAST TO REMAIN WEAKLY POSITIVE THROUGH DAY 10
THEN TREND TOWARDS ZERO BY THE END OF THE WEEK 2 PERIOD.
 

THE OFFICIAL HEIGHT PROG FOR TODAY CONSISTS OF 30 PERCENT OF THE
ECMWF ENSEMBLE MEAN CENTERED ON DAY 7...15 PERCENT EACH OF TODAYS  
GFS AND CANADIAN ENSEMBLE MEANS CENTERED ON DAY 8... AND 10 PERCENT 
EACH OF TODAYS 0Z AND 6Z GFS CENTERED ON DAY 8...HIGH RESOLUTION ECMWF 
CENTERED ON DAY 7 AND DAVA CENTERED ON DAY 8. 

MODEL OF THE DAY: ECMWF ENSEMBLE MEAN DUE TO A CONTINUATION OF 
SUPERIOR 500-HPA ANOMALY CORRELATIONS OVER THE PAST 60 DAYS. 

FORECAST CONFIDENCE FOR THE 6 TO 10 DAY PERIOD IS JUDGED TO BE ABOUT
AVERAGE TODAY...3 ON A SCALE FROM 1 TO 5...DUE TO GOOD AGREEMENT
AMONG MOST MODELS AND FORECAST TOOLS TEMPERED BY A CHANGE IN 
CONTINUITY IN THE HIGH RESOLUTION ECMWF SOLUTION.

THE 6 TO 10 DAY TEMPERATURE PROG IS BASED ON KLEIN AND NEURAL NET
SPECIFICATIONS AND ANALOGS TO THE 500-HPA BLEND... THE 850-HPA 
BIAS CORRECTED TEMPERATURES FROM THE 0PERATIONAL 0Z GFS AND 
TELECONNECTIONS ON A POSITIVE ANOMALY CENTER AT 43N 112W.

THE 6 TO 10 DAY PRECIPITATION PROG IS BASED ON NEURAL NET
SPECIFICATIONS AND ANALOGS TO THE 500-HPA BLEND... CPC 
CALIBRATED PRECIPITATION FROM THE GFS ENSEMBLE MEAN AND PERCENTAGES
FROM THE GFS ENSEMBLE MEMBERS... CPC BIAS CORRECTED PRECIPITATION
FROM THE 0Z GFS AND THE GFS ENSEMBLE MEAN AND TELECONNECTIONS ON
A POSITIVE ANOMALY CENTER AT 43N 112W.

         .         .         .         .         .         .         .
8 TO 14 DAY OUTLOOK FOR APR 29 - MAY 5 2004

THE OZ OPERATIONAL GFS FORECASTS THE CIRCULATION PATTERN TO BE VERY
SLOWLY PROGRESSIVE DURING THE WEEK 2 PERIOD. THE TROUGH CENTERED EAST
OF THE GREAT LAKES IS PROGGED TO LIFT OUT TO THE NORTHEAST...THE 
SOUTHERN PART OF THE RIDGE NEAR THE ROCKIES IS PROGGED TO EDGE SLOWLY
EASTWARD WHILE THE NORTHERN PART OF THE RIDGE REMAINS NEARLY FIXED IN
PLACE...AND THE TROUGH IN THE EASTERN PACIFIC SLOWLY APPROACHES THE
WEST COAST. THE 6Z GFS IS VERY SIMILAR TO THE 0Z OPERATIONAL GFS
EXCEPT IT IS MUCH LESS AMPLIFIED WITH THE NORTHERN PORTION OF THE 
RIDGE CENTERED NEAR THE ROCKIES. THE GFS ENSEMBLE MEAN IS AS USUAL
LESS AMPLIFIED THAN THE 0Z OPERATIONAL GFS AND IS ALSO SLIGHTLY LESS
PROGRESSIVE. THE DAVA ONCE AGAIN TODAY DEPICTS A COAST TO COAST ZONAL
FLOW PATTERN AND WAS DISCOUNTED. THE MODELS SHOW GOOD CONTINUITY WITH
RESPECT TO THEIR SOLUTIONS FROM YESTERDAY. THE GFS ENSEMBLE SPAGHETTI
DIAGRAMS INDICATE A RELATIVELY LARGE AMOUNT OF SPREAD AMONG THE
MEMBERS.

THE OFFICIAL 500-HPA HEIGHT PROG FOR TODAY CONSISTS OF 70 PERCENT OF
TODAYS GFS ENSEMBLE MEAN CENTERED ON DAY 11...20 PERCENT OF THE 0Z
GFS CENTERED ON DAY 11 AND 10 PERCENT OF THE 6Z GFS CENTERED ON DAY
11.

FORECAST CONFIDENCE FOR THE 8 TO 14 DAY PERIOD IS JUDGED TO BE ABOUT
AVERAGE TODAY...3 ON A SCALE OF 1 TO 5.

THE 8 TO 14 DAY TEMPERATURE PROG IS BASED ON KLEIN AND NEURAL NET
SPECIFICATIONS FROM THE BLEND AND ANALOGS TO THE BLEND AND THE 
850-HPA BIAS CORRECTED TEMPERATURES FROM THE 0Z OPERATIONAL GFS.

THE 8 TO 14 DAY PRECIPITATION PROG IS BASED ON NEURAL NET
SPECIFICATIONS AND ANALOGS TO THE 500-HPA BLEND... CPC
CALIBRATED PRECIPITATION FROM THE 0Z OPERATIONAL GFS AND PERCENTAGES
FROM THE GFS ENSEMBLE MEMBERS AND CPC BIAS CORRECTED PRECIPITATION
FROM THE 0Z GFS AND THE GFS ENSEMBLE MEAN.

FORECASTER: R. SCHECHTER
         .         .         .         .         .         .         .
NOTES: 

AUTOMATED FORECASTS ARE ISSUED ON SATURDAY AND SUNDAY.  OTHERWISE -
FORECASTS INCORPORATE FORECASTER INPUT.

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

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 NARRATIVE DESCRIPTION OF THE FORECAST PATTERNS FOR TEMPERATURE
AND PRECIPITATION FOR BOTH THE 6-10 OR 8-14 DAY PERIODS HAS BEEN
DISCONTINUED.  THE STATE TABLES FOR BOTH THE 6-10 AND 8-14 DAY
PERIODS ARE NOW CONTAINED IN THIS MESSAGE...AVAILABLE AS PMDMRD ON
AWIPS. 

EFFECTIVE THURSDAY MAY 17 2001...THE CLIMATE PREDICTION CENTER
HAS SWITCHED TO 1971-2000 BASE PERIOD MEANS FOR TEMPERATURE...
PRECIPITATION...AND 500-HPA HEIGHTS AS REFERENCE IN THE CLIMATE
OUTLOOKS.  THE 1971-2000 BASE PERIOD MEANS HAVE REPLACED THE
1961-1990 BASE PERIOD MEANS.
 
THE NEXT MONTHLY AND SEASONAL OUTLOOKS WILL BE RELEASED THURSDAY
MAY 20TH.





NEW NOTE EFFECTIVE MAR 16 2004:
THE GLOSSARY FORMERLY FOUND AT THIS LOCATION WILL NO LONGER BE
TRANSMITTED AS PART OF THIS MESSAGE. IF YOU WISH TO SEE THE
DEFINITIONS OF TERMS USED IN THESE MESSAGES... PLEASE GO TO THE
CPC WEB PAGE AT (USE LOWER CASE) HTTP://WWW.CPC.NCEP.NOAA.GOV
AND FOLLOW THE APPROPRIATE LINKS.

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: 
19510424 - 19780404 - 19670403 - 19670406 - 19570420
 
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:
19670403 - 19670406 - 19510423 - 19740430 - 19780404
 
6 to 10 day Outlook Table
OUTLOOK FOR APR 27 - MAY 01, 2004
 
STATE      TEMP PCPN   STATE      TEMP PCPN   STATE      TEMP PCPN   
WASHINGTON  A    B     OREGON      A    B     NRN CALIF   A    B     
SRN CALIF   A    N     IDAHO       A    B     NEVADA      A    B     
W MONTANA   A    B     E MONTANA   A    B     WYOMING     A    B     
UTAH        A    B     ARIZONA     A    N     COLORADO    A    N     
NEW MEXICO  N    N     N DAKOTA    A    B     S DAKOTA    A    B     
NEBRASKA    A    B     KANSAS      A    B     OKLAHOMA    A    B     
N TEXAS     N    B     S TEXAS     B    N     W TEXAS     N    N     
MINNESOTA   A    B     IOWA        A    B     MISSOURI    N    B     
ARKANSAS    N    B     LOUISIANA   B    N     WISCONSIN   A    B     
ILLINOIS    N    B     MISSISSIPPI N    N     MICHIGAN    N    B     
INDIANA     N    B     OHIO        N    B     KENTUCKY    N    B     
TENNESSEE   N    B     ALABAMA     B    N     NEW YORK    B    N     
VERMONT     B    N     NEW HAMP    B    N     MAINE       B    N     
MASS        B    A     CONN        N    A     RHODE IS    N    A     
PENN        N    N     NEW JERSEY  N    A     W VIRGINIA  N    N     
MARYLAND    N    A     DELAWARE    N    A     VIRGINIA    B    N     
N CAROLINA  B    A     S CAROLINA  B    A     GEORGIA     B    N     
FL PNHDL    B    A     FL PENIN    N    A     AK N SLOPE  N    N     
AK ALEUTIAN B    N     AK WESTERN  B    A     AK INT BSN  B    N     
AK S INT    B    A     AK SO COAST B    A     AK PNHDL    N    A     
 
 
8 to 14 day Outlook Table
OUTLOOK FOR APR 29 - MAY 05, 2004
 
STATE      TEMP PCPN   STATE      TEMP PCPN   STATE      TEMP PCPN   
WASHINGTON  A    N     OREGON      A    N     NRN CALIF   N    N     
SRN CALIF   A    N     IDAHO       A    B     NEVADA      A    B     
W MONTANA   A    B     E MONTANA   A    B     WYOMING     A    B     
UTAH        A    B     ARIZONA     A    N     COLORADO    A    N     
NEW MEXICO  A    N     N DAKOTA    A    B     S DAKOTA    A    B     
NEBRASKA    A    B     KANSAS      A    B     OKLAHOMA    A    B     
N TEXAS     N    B     S TEXAS     B    N     W TEXAS     N    N     
MINNESOTA   A    B     IOWA        A    B     MISSOURI    N    B     
ARKANSAS    N    B     LOUISIANA   B    N     WISCONSIN   A    B     
ILLINOIS    N    B     MISSISSIPPI B    N     MICHIGAN    N    B     
INDIANA     N    B     OHIO        N    B     KENTUCKY    N    B     
TENNESSEE   B    N     ALABAMA     B    N     NEW YORK    N    N     
VERMONT     N    N     NEW HAMP    N    N     MAINE       N    N     
MASS        N    N     CONN        N    N     RHODE IS    N    N     
PENN        N    B     NEW JERSEY  N    N     W VIRGINIA  B    N     
MARYLAND    N    N     DELAWARE    N    N     VIRGINIA    B    N     
N CAROLINA  B    N     S CAROLINA  B    N     GEORGIA     B    N     
FL PNHDL    B    A     FL PENIN    N    A     AK N SLOPE  B    N     
AK ALEUTIAN B    N     AK WESTERN  B    N     AK INT BSN  N    N     
AK S INT    N    A     AK SO COAST N    A     AK PNHDL    N    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.
 
$$