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FXUS06 KWBC 051905
PMDMRD
PROGNOSTIC DISCUSSIONS FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER CAMP SPRINGS MD
300 PM EDT FRI SEP 05 2008
6-10 DAY OUTLOOK VALID FOR SEP 11 - 15 2008
TODAYS MODELS ARE IN POOR AGREEMENT ON THE EXPECTED LARGE SCALE FEATURES OF THE
500-HPA CIRCULATION. THE MODELS CONSISTENTLY PREDICT A TROUGH OVER THE GULF OF
ALASKA SOUTH OF THE ALEUTIANS WITH A RIDGE DOWNSTREAM JUST OFF THE WEST COAST
OF NORTH AMERICA. INDIVIDUAL ENSEMBLE MEMBERS ARE FAIRLY EVENLY SPLIT BETWEEN
A TROUGH IN THE CENTRAL AND WESTERN PART OF THE CONUS AND A TROUGH IN THE
CENTRAL OR EASTERN U.S., AVERAGING IN THE ENSEMBLE MEANS TO WHAT APPEARS TO BE
A BROAD TROUGH OVER CENTRAL NORTH AMERICA. HURRICANE IKE COMPLICATES MATTERS
FURTHER WITH THE NATIONAL HURRICANE CENTER TRACK PLACING THE STORM IN THE
EASTERN GULF OF MEXICO BY DAY 5. THE TRACK OF IKE IS INFLUENCED BY THE
POSITION OF THE UPPER LEVEL TROUGH, WITH THE ENSEMBLE MEMBERS FAVORING THE
EASTERN TROUGH RECURVING THE STORM TO A GREATER EXTENT THAN MEMBERS WITH THE
TROUGH IN THE WEST. THIS STORM REQUIRES CLOSE WATCHING AND COULD BRING HEAVY
PRECIPITATION TO THE CENTRAL AND EASTERN GULF COAST AFTER PASSING FLORIDA PRIOR
TO THE START OF THE 6 TO 10 DAY PERIOD. AN ACTIVE FRONTAL BOUNDARY ASSOCIATED
WITH THE TROUGH EXPECTED TO BE IN THE CENTRAL U.S. ENHANCES CHANCES OF ABOVE
MEDIAN PRECIPITATION FOR MUCH OF THE EASTERN HALF OF THE CONUS. WET CONDITIONS
ARE EXPECTED FOR THE SOUTH COAST OF ALASKA AND THE ALASKAN PANHANDLE NEAR AN
ENHANCED PACIFIC STORM TRACK. THE WESTERN RIDGE FAVORS DRY CONDITIONS IN
NORTHERN PORTIONS OF THE GREAT BASIN WITH NORMALLY DRY CONDITIONS FURTHER
SOUTH. TEMPERATURES ARE EXPECTED TO BE BELOW NORMAL OVER MOST OF THE CENTRAL
PART OF THE U.S. UNDER THE UPPER LEVEL TROUGH. ABOVE NORMAL TEMPERATURES ARE
EXPECTED FOR PARTS OF THE GREAT BASIN AND MOST OF THE WEST COAST IN AREAS SOUTH
OF THE PACIFIC JET, ALTHOUGH THE POSSIBILITY OF A TROUGH OVER THE SOUTHWESTERN
CONUS AS SUGGESTED BY SOME ENSEMBLE MEMBERS DIMINISH CONFIDENCE IN THE FORECAST
FOR THIS REGION. BELOW NORMAL TEMPERATURES ARE EXPECTED FOR SOUTHERN AND
CENTRAL ALASKA UNDER AN EXPECTED UPPER LEVEL TROUGH.
TODAYS OFFICIAL 500-HPA BLEND CONSISTS OF 30 PERCENT OF TODAY'S GFS
SUPERENSEMBLE MEAN CENTERED ON DAY 8...30 PERCENT OF TODAY'S CANADIAN ENSEMBLE
MEAN CENTERED ON DAY 8...AND 40 PERCENT OF TODAY'S EUROPEAN ENSEMBLE MEAN
CENTERED ON DAY 7.
MODEL(S) OF THE DAY: ECMWF ENSEMBLE MEAN
FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD IS MUCH BELOW AVERAGE, 1 ON A SCALE
OF 1 TO 5, DUE TO MODEL DISAGREEMENT ON THE UPPER LEVEL CIRCULATION FEATURES
EXPECTED OVER THE CONUS AND UNCERTAINTY IN THE TRACK OF HURRICANE IKE.
THE 6-10 DAY TEMPERATURE PROG IS BASED ON THE KLEIN AND ANALOG SPECIFICATIONS
FROM THE OFFICIAL BLEND, THE NORTH AMERICAN ENSEMBLE FORECAST SYSTEM (NAEFS)
TEMPERATURE FORECASTS, AND THE AUTO TEMPERATURE FORECAST.
THE 6-10 DAY PRECIPITATION PROG IS BASED ON THE ANALOG SPECIFICATIONS FROM THE
OFFICIAL BLEND AND VARIOUS ENSEMBLE MEAN FORECASTS, THE AUTO PRECIPITATION
FORECAST, AND THE NORTH AMERICAN ENSEMBLE FORECAST SYSTEM (NAEFS) PRECIPITATION
PROBABILITY FORECASTS.
8-14 DAY OUTLOOK FOR SEP 13 - 19 2008:
THE PREDICTED 8-14 DAY MEAN 500-HPA CIRCULATION PATTERN SHOWS A PROGRESSION OF
THE MEAN TROUGH POSITION FROM CENTRAL TO THE EASTERN U.S. BETWEEN THE 6 TO 10
DAY AND 8 TO 14 DAY PERIOD. CONFIDENCE IN THIS FORECAST IS LOW, HOWEVER, IN
VIEW OF THE HIGH AMOUNT OF SPREAD IN SOLUTIONS AMONG INDIVIDUAL ENSEMBLE
MEMBERS. PRECIPITATION ASSOCIATED WITH FRONTAL SYSTEMS IN THE EAST-CENTRAL AND
EASTERN PART OF THE COUNTRY MAY BE ENHANCED WITH MOISTURE FROM HURRICANE IKE.
MANY TOOLS SUGGEST ABOVE MEDIAN PRECIPITATION FROM THE SOUTHERN GREAT PLAINS TO
THE UPPER MISSISSIPPI VALLEY. TEMPERATURES ARE EXPECTED TO BE SLIGHTLY COOL
FOR THIS TIME OF YEAR OVER THE CENTRAL PART OF THE COUNTRY, ALTHOUGH CONFIDENCE
IN TEMPERATURES IS QUITE LOW. BELOW NORMAL TEMPERATURES ARE EXPECTED FOR MUCH
OF ALASKA, UNDER THE UPPER LEVEL TROUGH, ALTHOUGH THIS DEPENDS TO SOME EXTENT
ON THE STRENGTH OF EXPECTED RIDGE OVER WESTERN NORTH AMERICA. AN ENHANCED
PACIFIC JET IS EXPECTED TO FAVOR ABOVE MEDIAN PRECIPITATION AMOUNTS FOR EASTERN
PARTS OF ALASKAS SOUTH COAST AND THE ALASKAN PANHANDLE.
THE OFFICIAL 8-14 DAY HEIGHT PROG CONSISTS OF 30 PERCENT OF TODAY'S OPERATIONAL
6Z GFS CENTERED ON DAY 11...40 PERCENT OF TODAY'S GFS SUPERENSEMBLE MEAN
CENTERED ON DAY 11...AND 30 PERCENT OF TODAY'S CANADIAN ENSEMBLE MEAN CENTERED
ON DAY 11.
FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD IS MUCH BELOW AVERAGE, 1 ON A SCALE
OF 1 TO 5, DUE TO MODEL DISAGREEMENT ON THE UPPER LEVEL CIRCULATION FEATURES
EXPECTED OVER THE CONUS AND UNCERTAINTY IN THE TRACK OF HURRICANE IKE.
THE 8-14 DAY TEMPERATURE PROG IS BASED ON THE KLEIN AND ANALOG SPECIFICATIONS
FROM THE OFFICIAL BLEND, AND TEMPERATURES FROM THE NORTH AMERICAN ENSEMBLE
FORECAST SYSTEM (NAEFS).
THE 8-14 DAY PRECIPITATION PROG IS BASED ON THE ANALOG SPECIFICATION FROM THE
OFFICIAL BLEND, THE NORTH AMERICAN ENSEMBLE FORECAST SYSTEM (NAEFS)
PRECIPITATION PROBABILITY FORECAST, AND THE AUTO BLEND PRECIPITATION FORECAST.
FORECASTER: UNGER
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:
19810904 - 19820913 - 19920822 - 19910914 - 19930826
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:
19810903 - 19800822 - 19960907 - 19870815 - 19920822
6 TO 10 DAY OUTLOOK TABLE
OUTLOOK FOR SEP 11 - 15, 2008
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON N N OREGON A B NRN CALIF A B
SRN CALIF A N IDAHO N B NEVADA A B
W MONTANA N B E MONTANA B B WYOMING B B
UTAH N B ARIZONA N N COLORADO B A
NEW MEXICO B A N DAKOTA B B S DAKOTA B B
NEBRASKA B A KANSAS B A OKLAHOMA B A
N TEXAS B A S TEXAS N B W TEXAS B A
MINNESOTA B N IOWA B A MISSOURI B A
ARKANSAS B A LOUISIANA N A WISCONSIN B N
ILLINOIS B A MISSISSIPPI N A MICHIGAN B A
INDIANA B A OHIO B A KENTUCKY B A
TENNESSEE B A ALABAMA N A NEW YORK N A
VERMONT A A NEW HAMP A A MAINE A A
MASS A A CONN A A RHODE IS A A
PENN N A NEW JERSEY N A W VIRGINIA N A
MARYLAND N A DELAWARE N A VIRGINIA N A
N CAROLINA N A S CAROLINA N A GEORGIA N A
FL PNHDL N A FL PENIN A A AK N SLOPE B B
AK ALEUTIAN B B AK WESTERN B B 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 SEP 13 - 19, 2008
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON N N OREGON A B NRN CALIF A B
SRN CALIF A N IDAHO A B NEVADA A B
W MONTANA A B E MONTANA N B WYOMING N B
UTAH A B ARIZONA A N COLORADO B B
NEW MEXICO N N N DAKOTA B B S DAKOTA B B
NEBRASKA B N KANSAS B A OKLAHOMA B A
N TEXAS B A S TEXAS N B W TEXAS N A
MINNESOTA B A IOWA B A MISSOURI B A
ARKANSAS B A LOUISIANA N A WISCONSIN B A
ILLINOIS B A MISSISSIPPI B A MICHIGAN B A
INDIANA B A OHIO B A KENTUCKY B A
TENNESSEE B A ALABAMA B A NEW YORK A A
VERMONT A A NEW HAMP A A MAINE A A
MASS A A CONN A A RHODE IS A A
PENN N A NEW JERSEY N A W VIRGINIA N A
MARYLAND N A DELAWARE N A VIRGINIA N A
N CAROLINA N A S CAROLINA N A GEORGIA N A
FL PNHDL N A FL PENIN N N AK N SLOPE N N
AK ALEUTIAN B B AK WESTERN N B AK INT BSN B N
AK S INT B A AK SO COAST B 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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