PROGNOSTIC DISCUSSIONS FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER CAMP SPRINGS MD
300 PM EDT MON OCT 11 2004
 
6 TO 10 DAY OUTLOOK FOR OCTOBER 17 - OCTOBER 21 2004
         .         .         .         .         .         .         .
DURING THE 6-10 DAY PERIOD THE MODELS FORECAST A DEAMPLIFICATION  
OF THE OVERALL CIRCULATION PATTERN FROM THAT FORECAST FOR DAYS 1-5.
A BROADLY CYCLONIC FLOW IS FORECAST ACROSS MOST OF THE CONUS WITH
A HANG-BACK TROUGH EXTENDING SOUTHWESTWARD INTO THE EASTERN PACIFIC
OFF THE CALIFORNIA COAST. HEIGHTS ARE FORECAST TO BE BELOW NORMAL 
ACROSS MOST OF THE CONUS...EXCEPT OVER THE EXTREME NORTHEASTERN
PART OF NEW ENGLAND AND OVER THE SOUTHWEST U.S. THE OPERATIONAL ECMWF
IS A BIT SLOWER TO LOWER HEIGHTS OVER THE EASTERN U.S. COMPARED TO
THE OTHER MODEL SOLUTIONS. THE BROADLY CYCLONIC FLOW SHOULD BRING 
COOL AND WET CONDITIONS TO MUCH OF THE NORTHERN TIER OF STATES.
THE MODELS TODAY ARE A LITTLE LESS PROGRESSIVE WITH THE MAIN 
CIRCULATION FEATURES COMPARED TO YESTERDAY BUT OTHERWISE SHOW GOOD
CONTINUITY. THE ENSEMBLE SPAGHETTI DIAGRAMS INDICATE RELATIVELY
LITTLE SPREAD TODAY EXCEPT ALONG THE WEST COAST AND OVER THE
EASTERN PACIFIC...MAINLY IN REGARD TO THE POSITION OF THE TROUGH 
FORECAST WEST OF THE CALIFORNIA COAST. THE PNA INDEX WHICH RECENTLY
HAS TRENDED WEAKLY POSITIVE IS FORECAST BY THE GFS ENSEMBLE  MEAN TO
BECOME NEGATIVE BY DAY 7 AND REMAIN NEGATIVE THROUGH DAY 10 AND THEN 
TREND TOWARDS ZERO BY THE END OF THE WEEK 2 PERIOD. THE NAO INDEX 
WHICH RECENTLY HAS BEEN NEGATIVE IS FORECAST TO REMAIN NEGATIVE
THROUGH THE NEXT TWO WEEKS. BOTH INDICES SHOW A LARGE AMOUNT OF 
SPREAD AMONG THE INDIVIDUAL ENSEMBLE MEMBERS SO CONFIDENCE IS LOW
WITH RESPECT TO THE FORECAST OF THE PHASE OF THE PNA AND NAO.
 
THE OFFICIAL D+8 HEIGHT PROG CONSISTS OF 20 PERCENT OF TODAYS GFS 
ENSEMBLE MEAN CENTERED ON DAY 8... 25 PERCENT OF THE MOST RECENT 
ECMWF ENSEMBLE MEAN CENTERED ON DAY 7... 15 PERCENT OF THE 
OPERATIONAL ECMWF CENTERED ON DAY 7...  10 PERCENT EACH OF TODAYS 
0Z AND 6Z GFS CENTERED ON DAY 8... 15 PERCENT OF TODAYS CANADIAN
ENSEMBLE MEAN CENTERED ON DAY 8 AND 5 PERCENT OF TODAYS DAVA 
CENTERED ON DAY 8.

MODEL OF THE DAY: ECMWF ENSEMBLE MEAN

FORECAST CONFIDENCE FOR THE 6 TO 10 DAY PERIOD IS ABOVE AVERAGE
TODAY...4 ON A SCALE FROM 1 TO 5.

THE 6 TO 10 DAY TEMPERATURE PROG IS BASED ON THE KLEIN AND ANALOG
SPECIFICATIONS FROM THE OFFICIAL 500-HPA BLEND... THE CDC CALIBRATED 
TEMPERATURE FORECAST AND THE BIAS CORRECTED 0Z GFS 850-HPA 
TEMPERATURE FORECAST. 

THE 6 TO 10 DAY PRECIPITATION PROG IS BASED ON CALIBRATED PRECIP-
ITATION PERCENTAGES FROM THE GFS ENSEMBLE MEMBERS...THE NEURAL NET 
AND ANALOG PRECIPITATION SPECIFICATIONS FROM THE 500-HPA BLEND...
BIAS CORRECTED PRECIPITATION FROM THE GFS ENSEMBLE MEAN AND THE CDC
CALIBRATED PRECIPITATION FORECAST.
         .         .         .         .         .         .         .
8 TO 14 DAY OUTLOOK FOR OCTOBER 19 - OCTOBER 25 2004

DURING WEEK 2 THE GFS ENSEMBLE MEAN FORECASTS LITTLE CHANGE TO THE 
OVERALL CIRCULATION PATTERN FROM THAT FORECAST FOR THE 6-10 DAY 
PERIOD. HEIGHTS ARE FORECAST TO RISE OVER THE EASTERN U.S. BUT MOST
OF THE CONUS CONTINUES TO BE FORECAST TO BE DOMINATED BY A BROAD
CYCLONIC FLOW. THE 6Z GFS IS THE MOST AMPLIFIED WITH THE FORECAST 
PATTERN AS IT BUILDS A RIDGE IN THE EAST AND PHASES THE NORTHERN
AND SOUTHERN JET STREAMS IN THE WEST...THUS DEEPENING A TROUGH ALONG
THE WEST COAST. THE DAVA IS SIMILAR TO THE GFS ENSEMBLE MEAN EXCEPT
IT IS QUICKER TO RAISE HEIGHTS IN WESTERN CANADA. THE TROUGH FORECAST
IN THE WEST SHOULD LEAD TO BELOW NORMAL TEMPERATURES AND ABOVE NORMAL 
PRECIPITATION OVER MUCH OF THE WESTERN U.S. WHILE THE BUILDING RIDGE
IN THE EAST SHOULD LEAD TO ABOVE NORMAL TEMPERATURES AND BELOW NORMAL
PRECIPITATION OVER THE EASTERN THIRD OF THE CONUS. THE MODELS SHOW GOOD
CONTINUITY WITH RESPECT TO THEIR SOLUTIONS FROM YESTERDAY...THOUGH THE
6Z GFS IS A BIT LESS PROGRESSIVE TODAY COMPARED TO ITS PREVIOUS 
FORECAST. THE GFS ENSEMBLE SPAGHETI DIAGRAMS INDICATE A MODERATE AMOUNT
OF SPREAD TODAY...ESPECIALLY OVER THE EAST PACIFIC AND ALONG THE 
NORTHERN TIER STATES.

THE OFFICIAL 8-14 DAY HEIGHT PROG CONSISTS OF 50 PERCENT OF TODAYS
GFS ENSEMBLE MEAN CENTERED ON DAY 11... 15 PERCENT OF TODAYS 0Z GFS
CENTERED ON DAY 11... 25 PERCENT OF TODAYS 6Z GFS CENTERED ON 
DAY 11 AND 10 PERCENT OF TODAYS DAVA CENTERED ON DAY 11.   

FORECAST CONFIDENCE FOR THE 8 TO 14 DAY PERIOD IS ABOVE AVERAGE 
TODAY... 4 ON A SCALE OF 1 TO 5.  
 

THE 8 TO 14 DAY TEMPERATURE PROG IS BASED ON THE KLEIN... ANALOG 
AND NEURAL NET SPECIFICATIONS FROM THE OFFICIAL 500-HPA BLEND...  
THE CDC CALIBRATED  TEMPERATURE FORECAST AND THE BIAS CORRECTED 0Z
GFS 850-HPA TEMPERATURE FORECAST.
 

THE 8 TO 14 DAY PRECIPITATION PROG IS BASED ON ANALOG AND NEURAL NET 
SPECIFICATIONS FROM THE OFFICIAL 500-HPA PROG...CALIBRATED PRECIP-
ITATION PERCENTAGES FROM THE GFS ENSEMBLE MEMBERS... BIAS CORRECTED 
PRECIPITATION FROM THE 0Z OPERATIONAL GFS AND GFS ENSEMBLE MEAN AND
THE CDC CALIBRATED PRECIPITATIN FORECAST. 

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...
OCTOBER 21.





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: 
19631020 - 19631023 - 19841009 - 19831020 - 19651018
 
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:
19631021 - 19631024 - 19790927 - 19561016 - 19841009
 
6 to 10 day Outlook Table
OUTLOOK FOR OCT 17 - 21, 2004
 
STATE      TEMP PCPN   STATE      TEMP PCPN   STATE      TEMP PCPN   
WASHINGTON  B    A     OREGON      B    A     NRN CALIF   N    A     
SRN CALIF   N    A     IDAHO       B    A     NEVADA      N    A     
W MONTANA   B    A     E MONTANA   B    A     WYOMING     N    A     
UTAH        N    N     ARIZONA     A    N     COLORADO    A    B     
NEW MEXICO  A    B     N DAKOTA    B    A     S DAKOTA    N    A     
NEBRASKA    N    N     KANSAS      A    B     OKLAHOMA    A    B     
N TEXAS     A    B     S TEXAS     A    B     W TEXAS     A    B     
MINNESOTA   B    A     IOWA        N    A     MISSOURI    N    N     
ARKANSAS    A    N     LOUISIANA   A    N     WISCONSIN   B    A     
ILLINOIS    B    A     MISSISSIPPI A    N     MICHIGAN    B    A     
INDIANA     B    A     OHIO        B    A     KENTUCKY    B    A     
TENNESSEE   B    N     ALABAMA     N    N     NEW YORK    B    A     
VERMONT     N    A     NEW HAMP    N    A     MAINE       A    A     
MASS        A    A     CONN        N    A     RHODE IS    N    A     
PENN        B    N     NEW JERSEY  B    N     W VIRGINIA  B    N     
MARYLAND    B    N     DELAWARE    B    N     VIRGINIA    B    N     
N CAROLINA  B    N     S CAROLINA  B    N     GEORGIA     N    N     
FL PNHDL    N    N     FL PENIN    N    B     AK N SLOPE  A    A     
AK ALEUTIAN A    N     AK WESTERN  A    A     AK INT BSN  N    A     
AK S INT    N    B     AK SO COAST B    B     AK PNHDL    B    B     
 
 
8 to 14 day Outlook Table
OUTLOOK FOR OCT 19 - 25, 2004
 
STATE      TEMP PCPN   STATE      TEMP PCPN   STATE      TEMP PCPN   
WASHINGTON  B    A     OREGON      B    A     NRN CALIF   B    A     
SRN CALIF   B    N     IDAHO       B    A     NEVADA      B    A     
W MONTANA   B    A     E MONTANA   B    A     WYOMING     B    A     
UTAH        B    A     ARIZONA     B    N     COLORADO    N    N     
NEW MEXICO  N    N     N DAKOTA    B    A     S DAKOTA    B    A     
NEBRASKA    N    N     KANSAS      N    A     OKLAHOMA    A    A     
N TEXAS     A    A     S TEXAS     A    N     W TEXAS     N    A     
MINNESOTA   N    A     IOWA        N    N     MISSOURI    A    A     
ARKANSAS    A    A     LOUISIANA   A    N     WISCONSIN   N    A     
ILLINOIS    A    N     MISSISSIPPI A    B     MICHIGAN    A    A     
INDIANA     A    N     OHIO        A    N     KENTUCKY    A    N     
TENNESSEE   A    B     ALABAMA     A    B     NEW YORK    A    N     
VERMONT     A    N     NEW HAMP    A    N     MAINE       A    B     
MASS        A    B     CONN        A    B     RHODE IS    A    B     
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  A    A     
AK ALEUTIAN A    N     AK WESTERN  A    A     AK INT BSN  A    A     
AK S INT    B    B     AK SO COAST B    B     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.
 
$$