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FXUS06 KWBC 252000
PMDMRD
PROGNOSTIC DISCUSSIONS FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER CAMP SPRINGS MD
300 PM EDT MON AUG 25 2008
6-10 DAY OUTLOOK VALID FOR AUG 31 - SEP 04, 2008
FOR THE MOST PART THE ENSEMBLE MEAN SOLUTIONS ARE IN GOOD AGREEMENT FOR THE
EXPECTED 500-HPA FLOW PATTERN OVER THE FORECAST DOMAIN. THE 0Z AND 6Z GFS
SOLUTIONS EXHIBIT GOOD CONTINUITY ON THE GENERAL LARGE SCALE MEAN PATTERNS FOR
THE UPCOMING PERIOD. THE ECMWF ENSEMBLE MEAN OFFERS CONSIDERABLE DISAGREEMENT
FOR THE BEHAVIOR AND EVOLUTION OF THE 500-HPA PATTERN ACROSS THE NORTHEAST
ATLANTIC JUST NORTHEAST OF THE US. THE DEVELOPMENT AND PERSISTENCE OF A BLOCK
TO THE NORTH AND A CUTOFF LOW IS THE MAJOR DIFFERENCE BETWEEN THE ECMWF
SOLUTION AND BOTH THE GFS AND CANADIAN ENSEMBLE MEAN SOLUTIONS. CONSEQUENTLY,
THE GFS AND CANADIAN ENSEMBLE MEAN FORECASTS WERE INCLUDED IN THE BLEND AND THE
ECMWF SOLUTION WAS NOT. OPERATIONAL RUNS OF THE GFS DURING THE 24 HOURS HAVE
VARIED WIDELY AND WERE NOT INCLUDED IN THE BLEND SOLUTION. BASED ON THE ABOVE
APPROACH, A STRONG TROUGH IS EXPECTED TO SITUATE ITSELF ALONG THE US WEST COAST
WITH A RATHER STRONG RIDGE ACROSS THE EASTERN 2/3 OF THE COUNTRY. AS A RESULT
OF THIS FORECAST PATTERN, ABOVE-AVERAGE TEMPERATURES AND BELOW-MEDIAN
PRECIPITATION IS EXPECTED TO DOMINATE THE NORTH-CENTRAL AND GREAT LAKES STATES.
NUMEROUS TROPICAL DISTURBANCES AND CONTINUED AMPLE MOISTURE FLOW ACROSS THE
GULF COAST INTO THE SOUTHWEST US IS EXPECETD TO KEEP TEMPERATURES AT OR
BELOW-AVERAGE. THE ABOVE-MENTIONED TROUGH ALONG THE WEST COAST IS EXPECTED TO
AID THE FLOW MONSOONAL MOISTURE AND RESULT IN ABOVE-MEDIAN PRECIPITATION ACROSS
THE SOUTHWEST US AND INTER-MOUNTAIN WEST DURING THE PERIOD. MOREOVER, THE
TROUGH ALONG THE WEST COAST SHOULD LEAD TO BELOW-MEDIAN PRECIPITION AND COOLER
THAN AVERAGE TEMPERATURES ACROSS PARTS OF THE PACIFIC NORTHWEST.
TODAYS OFFICIAL 500-HPA BLEND CONSISTS OF 40 PERCENT OF TODAY'S 0Z GFS ENSEMBLE
MEAN CENTERED ON DAY 8...40 PERCENT OF TODAY'S 6Z GFS ENSEMBLE MEAN CENTERED ON
DAY 8...AND 20 PERCENT OF TODAY'S CANADIAN ENSEMBLE MEAN CENTERED ON DAY 8.
MODEL(S) OF THE DAY: 00Z AND 06Z GFS ENSEMBLE MEANS
FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD IS ABOUT AVERAGE, 4 ON A SCALE OF 1
TO 5, DUE TO GENERALLY GOOD MODEL AND FORECAST TOOL AGREEMENT
THE 6-10 DAY TEMPERATURE PROG IS BASED ON THE KLEIN AND ANALOG SPECIFICATIONS
FROM THE OFFICIAL BLEND, THE AUTO TEMPERATURE FORECAST, THE NORTH AMERICAN
ENSEMBLE FORECAST SYSTEM (NAEFS) TEMPERATURE PROBABILITY FORECASTS, THE KLEIN
PROBABILITIES FROM THE VARIOUS ENSEMBLES, AND UNCALIBRATED AND CALIBRATED
TEMPERATURES FROM THE GFS ENSEMBLE MEAN.
THE 6-10 DAY PRECIPITATION PROG IS BASED ON THE ANALOG AND NEURAL NET
SPECIFICATIONS FROM THE OFFICIAL BLEND, THE AUTO PRECIPITATION FORECAST, THE
NORTH AMERICAN ENSEMBLE FORECAST SYSTEM (NAEFS) PRECIPITATION PROBABILITY
FORECASTS, AND NEURAL NET PROBABILITIES FROM THE VARIOUS ENSEMBLES
8-14 DAY OUTLOOK FOR SEP 02 - 08 2008:
FOR WEEK 2 THERE IS REASONABLY GOOD AGREEMENT BETWEEN THE GFS AND CANADIAN
ENSEMBLE MEAN SOLUTIONS WHICH GENERALLY REFLECT A SLIGHTLY DEAMPLIFIED 500-HPA
PATTERN THAN THAT SHOWN FOR THE 6-10 DAY PERIOD. THERE WILL CONTINUE TO BE A
TROUGH ALONG THE US WEST COAST WITH A STRONG RIDGE ACROSS THE EASTERN 2/3
THIRDS OF THE COUNTRY. THE MAIN DIFERENCE DURING THIS PERIOD FROM THE 6-10 DAY
PERIOD IS THE SUBSTANTIALLY DECREASED AGREEMENT IN THE FORECAST TOOLS
ESPECIALLY FOR PRECIPITATION. THEREFORE CONFIDENCE IS CONSIDERABLY LOWER FOR
THE WEEK 2 PERIOD. THE OFFICIAL BLEND IS BASED ON THE GFS AND CANADIAN ENSEMBLE
SOLUTIONS AS DURING THE EARLIER PERIOD. ABOVE-AVERAGE TEMPERATURES ARE EXPECTED
TO CONTINUE ACROSS MUCH OF THE NORTH-CENTRAL US AND GREAT LAKES WITH
BELOW-AVERAGE TEMPERATURES ACROSS PARTS OF THE PACIFIC NORTHWEST, SOUTHWEST US,
AND ALONG THE GULF COAST. OTHER THAN THE NORTHWEST US , THE BELOW-AVERAGE
TEMPERATURES ARE VERY MUCH RELATED TO ANTICIPATED INCREASED CLOUD COVER AND
PRECIPITATION. THE ABOVE-MEDIAN PRECIPITATION IS EXPECTED TO BE ORIENTED
FURTHER TO THE EAST THAN DURING THE 6-10 DAY PERIOD.
THE OFFICIAL 8-14 DAY HEIGHT PROG CONSISTS OF 40 PERCENT OF TODAY'S 0Z GFS
ENSEMBLE MEAN CENTERED ON DAY 11...40 PERCENT OF TODAY'S 6Z GFS ENSEMBLE MEAN
CENTERED ON DAY 11...AND 20 PERCENT OF TODAY'S CANADIAN ENSEMBLE MEAN CENTERED
ON DAY 11.
FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD IS NEAR AVERAGE, 3 ON A SCALE OF 1
TO 5 DUE TO FAIR AGREEMENT AMONG THE MODELS OFFSET BY RELATIVELY POOR AGREEMENT
AMONG THE FORECAST TOOLS. LARGE UNCERTAINTY EXISTS FOR FUTURE DEVELOPMENTS IN
THE TROPICS.
THE 8-14 DAY TEMPERATURE PROG IS BASED ON THE KLEIN AND ANALOG SPECIFICATIONS
FROM THE OFFICIAL BLEND, THE AUTO TEMPERATURE FORECAST, THE NORTH AMERICAN
ENSEMBLE FORECAST SYSTEM (NAEFS) TEMPERATURE PROBABILITY FORECASTS, AND THE
KLEIN PROBABILITIES FROM THE GFS AND CANADIAN ENSEMBLES.
THE 8-14 DAY PRECIPITATION PROG IS BASED ON THE NORTH AMERICAN ENSEMBLE
FORECAST SYSTEM (NAEFS) PRECIPITATION PROBABILITY FORECASTS AND THE AUTO BLEND
PRECIPITATION FORECAST
FORECASTER: GOTTSCHALCK
NOTES:
OPERATIONAL CHANGE: AS OF JULY 5 2005 SHADED MAPS HAVE REPLACED THE
CONTOUR-ONLY MAPS ON THE CPC WEB SITE. THE CONTOURED MAPS ARE
STILL AVAILABLE AT THEIR CURRENT FILE NAMES - SO DIRECT-LINKED USERS
ARE NOT AFFECTED. AWIPS GRAPHICS ARE ALSO NOT AFFECTED BY THIS
CHANGE.
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.
THE CLIMATE PREDICTION CENTER USES 1971-2000 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
SEPTEMBER 18
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:
19710908 - 19700814 - 19760827 - 19990825 - 19900805
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 5 DAY PERIODS CENTERED ON THE FOLLOWING DATES:
19710907 - 19990825 - 19670903 - 19850804 - 19760826
6 TO 10 DAY OUTLOOK TABLE
OUTLOOK FOR AUG 31 - SEP 04, 2008
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON B N OREGON B N NRN CALIF B N
SRN CALIF N N IDAHO B N NEVADA B A
W MONTANA N N E MONTANA N N WYOMING N A
UTAH B A ARIZONA B A COLORADO N A
NEW MEXICO N A N DAKOTA A N S DAKOTA A N
NEBRASKA A N KANSAS N N OKLAHOMA N N
N TEXAS N A S TEXAS N A W TEXAS N A
MINNESOTA A B IOWA A B MISSOURI A N
ARKANSAS N N LOUISIANA N A WISCONSIN A B
ILLINOIS A B MISSISSIPPI N A MICHIGAN A B
INDIANA A B OHIO A B KENTUCKY A N
TENNESSEE A N ALABAMA N N NEW YORK A B
VERMONT N B NEW HAMP N B MAINE N N
MASS N B CONN N B RHODE IS N B
PENN A B NEW JERSEY A B W VIRGINIA A B
MARYLAND A B DELAWARE A B VIRGINIA A N
N CAROLINA N N S CAROLINA N N GEORGIA N N
FL PNHDL N N FL PENIN B N AK N SLOPE A A
AK ALEUTIAN B A AK WESTERN N A AK INT BSN N A
AK S INT B A AK SO COAST B A AK PNHDL B N
8 TO 14 DAY OUTLOOK TABLE
OUTLOOK FOR SEP 02 - 08, 2008
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON B N OREGON B N NRN CALIF N N
SRN CALIF N N IDAHO B N NEVADA B N
W MONTANA N N E MONTANA N N WYOMING N A
UTAH B N ARIZONA B N COLORADO N A
NEW MEXICO B A N DAKOTA A A S DAKOTA A A
NEBRASKA A A KANSAS N A OKLAHOMA N A
N TEXAS B A S TEXAS B A W TEXAS B A
MINNESOTA A A IOWA A A MISSOURI N A
ARKANSAS N A LOUISIANA B A WISCONSIN A N
ILLINOIS A A MISSISSIPPI N A MICHIGAN A N
INDIANA A N OHIO A N KENTUCKY A N
TENNESSEE N A ALABAMA N A NEW YORK A B
VERMONT A B NEW HAMP A B 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 N
N CAROLINA N N S CAROLINA N N GEORGIA N A
FL PNHDL B A FL PENIN B A AK N SLOPE N A
AK ALEUTIAN N A AK WESTERN N A AK INT BSN N A
AK S INT N A AK SO COAST N A AK PNHDL B 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.
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